Question

Lin and Han's families provide money for their school lunch

accounts.
• Han starts with $100 in his account. He spends $15 each week
on lunches.
• Lin starts with $25 in her account and does not spend any of it.
Her family adds $10 each week to her account.
1. At the end of 4 weeks, who has more money in their account?
2. After how many weeks will Han and Lin have the same amount
of money in their lunch accounts?

Answer 1

1) after 4 weeks, Lin has more with $65

2) after 3 weeks they both have same amount

Explanation:

let 'w' = number of weeks

1) equation for Han: y = 100 - 15w

y = 100 - 15(4)

y = 100 - 60

y = $40 after 4 weeks

equation for Linn: y = 25 + 10w

y = 25 + 10(4)

y = 25 + 40

y = $65 after 4 weeks

2) 100 - 15w = 25 + 10w

75 - 15w = 10w

75 = 25w

w = 3 weeks