Ben had 6 times as many erasers as Neave at first. Then each of them bought an equal number of new erasers. In the end, Neave had 55 erasers and Ben had 3 times as many erasers as Neave. How many erasers did both of them buy altogether?
| |
Ben |
Neave |
Difference |
| Before |
6x2 =
12 u |
1x2 =
2 u |
5x2 =
10 u |
| Change |
+ ? |
+ ? |
|
| After |
3x5 =
15 u |
1x5 =
5 u |
2x5 =
10 u |
The difference in the number of erasers at first and in the end remains unchanged. Make the difference in the number of erasers at first and in the end the same. LCM of 5 and 2 is 10.
Number of erasers that Neave had in the end = 5 u
5 u = 55
1 u = 55 ÷ 5 = 11
Number of erasers that Ben bought
= 15 u - 12 u
= 3 u
Number of erasers that both of them bought altogether
= 2 x 3 u
= 6 u
= 6 x 11
= 66
Answer(s): 66
