Math question about coffee

Question

A store sells regular coffee for $5 a pound and gourmet coffee for $8 a pound. To get rid of 60 pounds of the gourmet coffee, a shopkeeper makes a blend to put on sale for $6 a pound. How many pounds of regular coffee should he use?

Answer 1

The boring way to solve 5x + 8(60) = 6(x+60). Solv for x,

The fun way: think of balancing a see-saw.

8 is 2 from 6 and 5 is 1 from 6, so the weight at 5 must be twice as much as the weight at 8. x = 2 * 60