Billy had 81 marbles more than Tommy at first. After Billy had given away 141 of his marbles to Ivan, Tommy had four times as many marbles as Billy. Find the number of marbles Billy had at first.
| |
Billy |
Tommy |
Comparing between
Billy and Tommy |
81 more |
|
| Before |
1 u + 141 |
4 u |
| Change |
- 141 |
|
| After |
1 u |
4 u |
Billy had 81 marbles more than Tommy at first.
If 81 more marbles is given to Tommy at first, both will have the same number of marbles.
4 u + 81 = 1 u + 141
4 u - 1 u = 141 - 81
3 u = 60
1 u = 60 ÷ 3 = 20
Number of marbles that Billy has at first
= 1 u + 141
= 20 + 141
= 161
Answer(s): 161
