Let us work with the options. For (a), total cost = 7$\times$480 + 2$\times$130=3620 For (b), total cost = 7$\times$480+3$\times$130=3750 For (c), total cost = 2$\times$ 480 + 7$\times$ 130 = 1870 Hence, option (a) is correct.
Two trains each of 120 m in length, run in opposite directions with a velocity of 40 m/s and 20 m/s respectively. How long will it take for the tail ends of the two trains to meet each other during the course of their journey ?
Pratul's monthly income is onefourth of Manoj's monthly income. Manoj's annual income is ` 2.16 lacs. What is Pratul's annual income? (In some cases monthly income and in some cases annual income are used.