a part of family expenses of a family is constant and the remaining varies with the price of the wheat. when the rate of wheat is Rs.250 per quintal, the total

Question

monthly of the family are rs.1000 and when it is rs 240 per quintal, the total monthly expenses are rs.980 find the monthly expenses of the family when the cost of wheat is rs.350 per quintal

 

Answer 1

assigning the constant expenses part b, the total expense can be expressed as

total expenses=m(price of the wheat)+b

change shape into

f(x)=mx+b

We have when x=250, f(x)=1000 and when x=240, f(x)=980

i.e. 1000=250m+b and 980=240m+b

Solve those: m=2, b=500

the monthly expenses of the family when the cost of wheat is rs.350 per quintal:

f(350)=2*350+500=1200