1 . 
The average age of 80 boys in a class is 15. The average age of a group of 15 boys in the class is 16 and the average age of another 25 boys in the class is 14. What is the average age of the remaining boys in the class ? 

Answer & Explanation
Answer : Option
A


Explanation : 







2 . 
In a class, the average height of 35 girls was measured 160 cm. Later on, it was discovered that the height of one of the girl was misread as 144 cm, while her actual height was 104 cm. What was the actual average height of girls in the class ? (rounded off to two digits after decimal) 

Answer & Explanation
Answer : Option
E


Explanation : 







3 . 
The average age of the family of five members is 24. If the present age of youngest member is 8 yr, then what was the average age of the family at the time of the birth of the youngest member ? 

Answer & Explanation
Answer : Option
B


Explanation : 

Total age of the family of five members = 24 $\times$ 5 = 120 Total age of the family of five members before 8 years = 120  5 $\times$ 8 = 120  40 = 80 So, Required average age = $80 \over 5$ = 16 yr 





4 . 
In a class, there are 32 boys and 28 girls. The average age of the boys in the class is 14 yr and the average age of the girls in the class is 13 yr. What is the average age of the whole class ? (Rounded off to two digits after decimal) 

Answer & Explanation
Answer : Option
B


Explanation : 







5 . 
The average marks of 65 students in a class was calculated as 150. It was later realised that the marks of one of the students was calculated as 142, whereas his actual marks were 152. What is the actual average marks of the group of 65 students ? (Rounded off to two digits after decimal) 

Answer & Explanation
Answer : Option
B


Explanation : 







6 . 
The total ages of a class of 75 girls is 1050, the average age of 25 of them is 12 yre and that of another 25 is 16 yr. Find the average age of the remaining girls. 

Answer & Explanation
Answer : Option
C


Explanation : 







7 . 
Average score of Rahul, Manish and Suresh is 63. Rahul's score is 15 less than Ajay and 10 more than Manish. If Ajay scored 30 marks more than the average scores of Rahul, Manish and Suresh, what is the sum of Manish's and Suresh's scores ? 

Answer & Explanation
Answer : Option
B


Explanation : 

Let the score of Ajay = $x$ Rahul = $x$  15 Manish = $x$  25 According to question, $x$ = 63 + 30 $x$ = 93 Score of Ajay = 93 then Rahul = 93  15 = 78 then Manish = 93  25 = 68 Total marks of Rahul, Manish and Suresh = 3 $\times$ 63 = 189 Suresh = 189  (78 + 68) = 43 Manish + Suresh = 68 + 43 = 111 





8 . 
The average weight of 45 students in a class was calculated as 36 kg. It was later found that the weight of two students in the class was wrongly calculated. The actual weight of one of the boys in the class was 32 kg. but it was calculated as 34 kg, and the weight of another boy in the class was 45 kg. whereas it was calculated as 40 kg. What is the actual average weight of the 45 students in the class ? (Rounded off to twodigits after decimal) 

Answer & Explanation
Answer : Option
A


Explanation : 







9 . 
The respective ratio between the speeds of a car, a train and a bus is 5 : 9 : 4. The average speed of the car, the bus and the train is 72 km/h together. What is the average speed of the car and the train together ? 

Answer & Explanation
Answer : Option
C


Explanation : 







10 . 
The total marks obtained by a student in physics, Chemistry and Mathematics together is 120 more than the marks obtained by him in Chemistry. What are the average marks obtained by him in Physics and Mathematics together ? 

Answer & Explanation
Answer : Option
A


Explanation : 

Suppose marks got in physics, chemistry and mathematics are P, C and M. P + C + M = C + 120 P + M = 120 ${P + M} \over 2$ = 60 





11 . 
The average marks in Science subject of a class of 20 students is 68. If the marks of two students were misread as 48 and 65 of the actual marks 72 and 61 respectively, then what would be the correct average ? 

Answer & Explanation
Answer : Option
B


Explanation : 

Difference of marks = 72 + 61  48  65 = 20 Correct average marks = 68 + $20 \over 20$ = 68 + 1 = 69 





12 . 
The average age of seven boys sitting in a row facing North is 26 yr. If the average age of first three boys is 19 yr and the average age of last three boys is 32 yr. What is the age of the boy who is sitting in middle of the row ? 

Answer & Explanation
Answer : Option
B


Explanation : 

(7 $\times$ 26)  (3 $\times$ 19 + 3 $\times$ 32) = 182  (57 + 96) = 182  153 = 29 yr 





13 . 
The average age of a group of 10 students is 15 yrs. When 5 more students joined the group the average age rose by 1 yr. The average age (in years) of the new students is 

Answer & Explanation
Answer : Option
A


Explanation : 

Total age of 10 students = 15 $\times$ 10 = 150 yrs Total age of 15 students = 15 $\times$ 16= 240 yrs Average of new students = ${240  150} \over 5$ = 18 yrs. 





14 . 
The average weight of 8 persons is increased by 2.5 kg when one of them who weighs 56 kg is replaced by a new man. The weight of the new man is 

Answer & Explanation
Answer : Option
E


Explanation : 

56 + 8 $\times$ 2.5 = 76 yrs 





15 . 
The average weight of A, B and C is 84 kg. If D joins the group, the average weight of the group becomes 80 kg. If another man E who weighs 3 kg more than D replaces A, then the average of B, C, D and E becomes 79 kg. What is the weight of A? 

Answer & Explanation
Answer : Option
E


Explanation : 

A + B + C = 3 $\times$ 84 = 252 kg A + B + C + D = 4 $\times$ 80 = 320 kg D = 320  252 = 68 kg E = 68 + 3 = 71 kg Now, ${320  A + 71} \over 4$ = 79 A = 75kg 





16 . 
The average salary of all the workers in a workshop is Rs. 8,000. The average salary of 7 technicians is Rs.12,000 and the average salary of the rest is Rs. 6,000. The total number of workers in the workshop is : 

Answer & Explanation
Answer : Option
A


Explanation : 

Let the total no. of workers be x. Now, 8000 x = 7 $\times$ 12000 + (x  7) $\times$ 6000 x = $42000 \over 2000$ = 21 





17 . 
The mean monthly salary paid to 75 workers in a factory is Rs.5,680. The mean salary of 25 of them is Rs. 5,400 and that of 30 others is Rs.5,700. The mean salary of the remaining workers is 

Answer & Explanation
Answer : Option
C


Explanation : 







18 . 
The average monthly expenditure of a family was Rs.2200 during the first 3 months; Rs.2250 during the next 4 months and Rs.3120 during the last 5 months of a year. If the total saving during the year were Rs.1260, then the average monthly income was 

Answer & Explanation
Answer : Option
C


Explanation : 

Total annual income = 3 $\times$ 2200 + 4 $\times$ 2250 + 5 $\times$ 3120 + 1260 = 6600 + 9000 + 15600 + 1260 = 32460 Average monthly income = $32460 \over 12$ = Rs.2705 





19 . 
The batting average of 40 innings of a cricket player is 50 runs. His highest score exceeds his lowest score by 172 runs. If these two innings are excluded, the average of the remaining 38 innings is 48. His highest score was : 

Answer & Explanation
Answer : Option
C


Explanation : 







20 . 
The average score of boys in an examination of a school is 71 and that of the girls is 73. The average score of the whole school in that examination is 71.8. Find the ratio of the number of boys to the number of girls that appeared in the examination. 

Answer & Explanation
Answer : Option
B


Explanation : 







21 . 
The average monthly salary of employees, consisting of officers and workers, of an organisation is Rs. 3000. The average salary of an officer is Rs. 10000 while that of a worker is Rs. 2000 per month. If there are a total 400 employees in the organisation, find the number of officers. 

Answer & Explanation
Answer : Option
A


Explanation : 







22 . 
The average marks of a student in 8 subjects is 87. Of these, the highest marks are 2 more than the one next in value. If these two subjects are eliminated, the average marks of the remaining subjects is 85. What is the highest score? 

Answer & Explanation
Answer : Option
B


Explanation : 







23 . 
In a famous hotel, the rooms are numbered from 101 to 130 on the first floor, 201 to 220 on the second floor and 301 to 330 on the third floor. In the month of September, the room occupancy was 50% on the first floor, 80% on the second floor and 40% on the third floor. If it is also known that the room charges are Rs. 200, Rs. 250 and Rs. 300 on each of the floors respectively, then find the average income per room in the hotel for the month of September? 

Answer & Explanation
Answer : Option
B


Explanation : 







24 . 
There were 46 students in a Boys hostel. Due to the admission of eight new students the expenses of the hostel mess were increased by Rs.42 per day while the average expenditure per head diminished by Rs 1. What was the original expenditure of the hostel mess? 

Answer & Explanation
Answer : Option
E


Explanation : 







25 . 
In Kiran's opinion, his weight is greater than 65 kg but less than 72 kg. His brother does not agree with Kiran and he thinks that Kiran's weight is greater than 60 kg but less than 70 kg. His mother's view is that his weight cannot be greater than 68 kg. If all are them are correct in their estimation, what is the average of different probable weights of Kiran? 

Answer & Explanation
Answer : Option
D


Explanation : 







26 . 
The average weight of the students in four sections A, B, C and D is 60 kg. The average weight of the students of A,B, C and D individually are 45kg, 50kg, 72 kg and 80 kg, respectively. If the average weight of the students of section A and B together is 48 kg and that of B and C together is 60kg, what is the ratio of the number of students in section A and D? 

Answer & Explanation
Answer : Option
C


Explanation : 







27 . 
The average temperature of the town in the first four days of a month was 58 degrees. The average for the second, third, fourth and fifth days was 60 degrees. If the temperatures of the first and fifth days were in the ratio 7 : 8, then what is the temperature on the fifth day ? 

Answer & Explanation
Answer : Option
B


Explanation : 







28 . 
The average price of 10 books is Rs. 12 while the average price of 8 of these books is Rs. 11.75. Of the remaining two books, if the price of one book is 60% more than the price of the other, what is the price of each of these two books ? 

Answer & Explanation
Answer : Option
B


Explanation : 







29 . 
The average age of a group of persons going for picnic is 16 years. Twenty new persons with an average age of 15 years join the group on the spot due to which their average age becomes 15.5 years. The number of persons initially going for picnic is : 

Answer & Explanation
Answer : Option
B


Explanation : 







30 . 
16 children are to be divided into two groups A and B of 10 and 6 children. The average percent marks obtained by the children of group A is 75 and the average percent marks of all the 16 children is 76. What is the average percent marks of children of group B? 

Answer & Explanation
Answer : Option
A


Explanation : 







