Question

The owner of a milk store finds that he can sell 980 litres of milk each week at Rs. 14 litre and 1220 litres of milk each week at Rs. 16 litre. Assuming a linear relationship between selling price and demand how many litres could he sell weekly at Rs. 17 litre?

Answer 1

Let the owner sell L litre of milk at Rs. p/ litre, then linear relationship between L and p be

OR

Let A=(14,980),B = (16,12200 then slope of

AB = (1220 - 980)/(16 - 14) = 240/2 = 120

Let owner can sell L litres of milk at Rs. 17 per litre. Then the point P(17, L) will lie on the

⇒ A, B and P are collinear

⇒ Sloe of AB = slope of BP

⇒ 120 = (L - 1220)/(17 - 16) = L - 1220

⇒ L = 120 + 1220 = 1340 litres

∴ The milk owner can sell 1340 litres of milk at Rs. 17 per litre.

Remark: This can be solve, using two-point form also.