Justin had 70 more marbles than Peter. Justin gave 20% of his marbles to Peter. Peter in return gave 50% of his marbles to Justin. In the end, Peter had 176 less marbles than Justin. How many marbles did Justin have at first?
| |
Justin |
Peter |
Comparing Justin
and Peter at first |
70 more |
|
| Before |
5 u + 70 |
5 u |
| Change 1 |
- 1 u - 14 |
+ 1 u + 14 |
| After 1 |
4 u + 56 |
6 u + 14 |
| Change 2 |
+ 3 u + 7 |
- 3 u - 7 |
| After 2 |
7 u + 63 |
3 u + 7 |
20% =
20100 =
1520% x 70
=
20100 x 70
= 14
50% x 14
=
50100 x 14
= 7
50% x 6 u
=
50100 x 6 u
= 3 u
Peter had 176 less marbles than Justin in the end. If another 176 marbles are given to Peter, both will have the same number of marbles.
7 u + 63 = 3 u + 7 + 176
7 u - 3 u = 7 + 176 - 63
4 u = 120
1 u = 120 ÷ 4 = 30
Number of Peter's marbles at first
= 5 u
= 5 x 30
= 150
Answer: 150
