Question

A part of the monthly expenses of a family is constant and the remaining varies with the price of wheat. When the rate of wheat is $Rs.250$ a quintal the monthly expenses of the family is $Rs.1000$ and when it is $Rs.240$ a quintal, the monthly expenses is $Rs.980$. Find the monthly expenses of the family on wheat the cost of wheat is $Rs.350$ a quintal,

Answer 1

Let the family buy's$x$ quantal wheat.

Let the constant expense be $y$.

When rate is $Rs.250$.

$250x+y=1000$

When rate is $Rs.240$.

$240x+y=980$.

Solving the above equations we get,

$x=2$ and $y=500$

When rate is $Rs.350$.

Monthly expenses$=350\times 2+500=Rs.1200$.