Suhas decided to donate 15% of his salary. On the day of donation he changed his mind and donated Rs. 1,650 whichwas $11\over 15$th of what he had decided to donate earlier. How much is Suhas' salary ?

Work done by A in one day is four times the work done by B in one day, while the work done by B in one day is onethird of the work done by C in one day. C alone can complete the work in 16 days. In how many days can all the three together complete the work ?

The total age of a class of 60 girls is 900 years. The average age of 20 of the girls is 12 years and that of the other 20 girls is 16 years. What is the average age of the remaining girls?

A and B started a business with initial investments in the respective ratio of 5 : 7. If after one year their profits were in the ratio 1 : 2 and the period for A's investement was 7 months, B invested the money for