question_answer

If 25 metres of costs Rs. 337.50, then

(a) What will be the cost of 40 metres of the same type of cloth?

(b) What will be the length of the cloth bought for Rs. 810?

Answer:

(a) Let cost of cloth be Rs. x.

Length of cloth (m)	25	40
Cost of cloth (Rs.)	Rs.337.50	x

Here, cost will be increase by increasing the length of cloth. Hence, it is directly proportional.   \[\frac{25}{337.5}=\frac{40}{x}\] \[x=\frac{337.5\times 40}{25}=\,Rs.\,540\]          (b) Let the length of cloth be y m.

Length of cloth (m)	25	Y
Cost of cloth (Rs.)	Rs.337.50	810

Here, as the length will increase by increasing the amount so, it is directly proportional.                                                            \[\frac{25}{337.5}=\frac{y}{810}\] \[\Rightarrow \,\]             \[y=\frac{25\times 810}{337.5}\] \[\Rightarrow \,\]               y = 60 metres.