1(x) + 2(x) + 6(x) = 300

Question

Joe has 6 times the money Bob has, Bob has 2 times the money Ann has, all together they have $300. How much does Ann have?

 

I know the answer ( by trial and error) that Ann has $20

 

I don't know a formula I can explain to my sixth grader...  I made up the formula above, but I don't know how to solve it...

Answer 1

A = money Anne has

2A = money Bob has

6(2A) = money Joe has     - six times Bob's

A + 2A + 12A = 300

15A = 300

A = 20