Harry started the day by trading 5of his comic books for7 of jenny's next he bought 8 at the store then he gave tom 9comic booksharry came home with 12 comic bookshow many did harry start the day?

Answer 1

11.


Let H be the number of comic books Harry started with.

He swapped 5 of his for 7 of Jenny's, so:

• He gave 5 to Jenny, meaning he now has: H - 5
  
• Received 7 from Jenny, meaning he now has: (H - 5) + 7 = H - 5 + 7 = H + 2
  

He bought 8 from the shop, so:

• He has 8 more, meaning he now has: (H + 2) + 8 = H + 2 + 8 = H + 10
  

He gave 9 to Tom, so:

• He has 9 fewer, meaning he now has: H + 10 - 9 = H + 1

He how has 12, so:

H + 1 = 12

→ H = 11