Question

Kath starts with a number. she adds 3 to her number then double the result. finally, she subtracts 7. if she ended with 9, what number did she start with?

Answer 1

The answer is 5. Work backwards: first add 7 to 9, then divide by 2, then subtract 3.

9+7=16
16/2=8
8-3=5

Cross Check:
5+3=8
8*2=16
16-7=9

Final Answer: 5