Question

9. The cost of 5 metres of cloth is Rs. 400. Find the cost of (i) 8 metres of cloth (ii) 18 metres
of cloth. (iii) Also, find the value of the constant of proportionality.​

Answer 1

Answer:

1. Rs.640 2.Rs.1440 3.80

Step-by-step explanation:

cost of 5m of cloth = Rs. 400

therefore, cost of 1m of cloth = Rs. 400/5 = Rs. 80

So, cost of 8m of cloth = Rs. 80*8 =Rs 640

and cost of 18m of cloth = Rs. 80*18 =Rs 1440

constant of proportionality = 80

We can observe that as length of cloth increase,price is also increased . We can say that length of cloth is directly proportional to cost of cloth.

Let k be the value of constant of proportionality.

To find k, we will use b= ka where b=cost of cloth and a = length of cloth

k = b/ a = 400/5 = 640/8 =1440/18 =80.

Therefore,value of the constant of proportionality=80