Question

I know that I need three equations to solve the system, but it seems like I don't have enough information to solve. I can do x+y+z=40 for one equation. But I'm not sure how to get the other two equations. Thanks for the help.
The college bookstore sells 3 types of calculators. They have a total of 40 calculators in stock. The total amount of revenue from these calculators will be ₹3590. The most expensive type costs ₹75 more than the cheapest. Find the cost of each type.

Answer 1

Answer:

Step-by-step explanation:

let the cost of cheapest one is x then expensive one costs 75+x

then cost of remaining one is y

let the number of calculators of each type be a,b and (40-a-b)

a number of calculators cost = ax

b number of calculators cost = by

40-a-b number of calculators cost = (40-a-b)(75+x)

total cost

ax+by+(40-a-b)(75+x)=3590

ax+by+3000+40x-75a-ax-75b-bx=3590

by-bx+40x-75a=590

(40-b)x+by=590+75a