Abi and Betty had an equal number of erasers at first. Abi used
14 of her erasers and Betty used
110 of her erasers. They used 28 erasers altogether. How many erasers did Betty have in the end?
|
Abi |
Betty |
Before |
4x5 = 20 u |
10x2 = 20 u |
Change |
- 1x5 = - 5 u |
- 1x2 = - 2 u |
After |
3x5 = 15 u |
9x2 = 18 u |
The number of erasers that Abi and Betty each had at first is the same. Make the number of erasers that Abi and Betty each had at first the same. LCM of 4 and 10 is 20.
Number of erasers that Abi and Betty used
= 5 u + 2 u
= 7 u
7 u = 28
1 u = 28 ÷ 7 = 4
Number of erasers that Betty had in the end
= 18 u
= 18 x 4
= 72
Answer(s): 72