# 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?

Let selling price is denoted by = Rs. Y and demand = x litre.

A.T.Q. y = ax + b …(i)

Now, when x = 980 litre, and y = Rs.14/litre

14 = 980 a + b …(ii)

Again when x = 1220 and y = Rs.16/litre

16 = 1220 a + b …(iii)

From (ii) and (iii), we get

1220a – 980 a = 2

or 240a = 2

or a = Putting the value of a in (ii)

980 × = 14

⇒ b = 14 - = = = Now a = and b = and y = 17

From y = ax + b

17 = × x +  × 17 -  - x = = 1340

Hence, x = 1340 litres.

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos  Various Forms of Equations of line45 mins  Slope, inclination and angle between two lines48 mins  Interactive Quiz on Equations of line23 mins  Parametric Equations of Straight line48 mins  Straight line | Analyse your learning through quiz56 mins  General Equation of a line43 mins  Motion in a Straight Line - 0665 mins  Motion in a Straight Line - 0556 mins  Motion in a Straight Line - 0372 mins  Understand The Interesting Concept Of Relative velocity in 1- Dimension44 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation view all courses 