Marco has $24. Mary has $15. If Marco gives Mary half of what he has, Mary will have more than Marco. But Mary spends $5. How much more money does Mary have than Marco?
Half of what Marco has is $24 / 2 = $<T>divide(24, 2)=12.0
If he gives Mary $12, she has $12 + $15 = $<T>add(12, 15)=27
Now subtract the money Mary spends: $27 - $5 = $<T>subtract(27, 5)=22
Now subtract Marco's money from Mary's remaining money, $22 - $12 = $<T>subtract(22, 12)=10
