Thread: Number calculation

Hi Experts,

The cost of 12 Chairs and 15 Tables is Rs 58,968. What is the cost of 4 Chairs and 7 Tables ?

1. 18666
2. 23456
3. 19656
4. Can not be Determined

Letting C be the cost of a chair and T be the cost of a table, we have 12C+ 15T= 58968. That is NOT enough to solve for either C or T. We could, for example, divide by 3 to get 4C+ 5T= 19656. But that is not "4C+ 5T". If we were able to determine 4C+ 7T= A, we could get, by subtracting, 2T= 19656- A and so solve for T and, of course, then, solve for C. Since, in fact, there exist an infinite number of values of T and C that satisfy 12C+ 15T= 58968, there are an infinite number of values of A in 4C+ 7T= A.

Thanks
HallsofIvy