Betty and Gem had an equal number of buttons at first. Betty used
12 of her buttons and Gem used
17 of her buttons. They used 72 buttons altogether. How many buttons did Gem have in the end?
|
Betty |
Gem |
Before |
2x7 = 14 u |
7x2 = 14 u |
Change |
- 1x7 = - 7 u |
- 1x2 = - 2 u |
After |
1x7 = 7 u |
6x2 = 12 u |
The number of buttons that Betty and Gem each had at first is the same. Make the number of buttons that Betty and Gem each had at first the same. LCM of 2 and 7 is 14.
Number of buttons that Betty and Gem used
= 7 u + 2 u
= 9 u
9 u = 72
1 u = 72 ÷ 9 = 8
Number of buttons that Gem had in the end
= 12 u
= 12 x 8
= 96
Answer(s): 96