back to *math video class*

- Example of word problem solving
- Question:
- Tom earns 10% more than Kevin and Kevin earns 3/5 of what John earns. What percent of John's earning is Tom's?

- Solution:
- translate the words into mathematics expression
- Let T be Tom's earning and K be Karen's earning
- Tom earns 10% more than Kevin
- T = K + (10/100)K = K(1 + 10/100) = K(1 + 1/10) = (11/10)K
- Kevin earns 3/5 of what John earns
- K = (3/5)J
- both side of the equation multiply 5
- 5K = 3J
- express J in terms of K
- J = (5/3)K
- What percent of John's earning is Tom's?
- T/J = [(11/10)K]/[(5/3)K] = (11/10)K ÷ (5/3)K = (11/10)K × (3/5K) = (11 × 3)/(10 × 5) = 33/50 = 66/100
- so T = (66/100)J
- Tom's earning is 66/100 of John's earning.