Bobby had 140 more pens than Peter. Bobby gave 20% of his pens to Peter. Peter in return gave 50% of his pens to Bobby. In the end, Bobby had 365 more pens than Peter. How many pens did Bobby have at first?
| |
Bobby |
Peter |
Comparing Bobby
and Peter at first |
140 more |
|
| Before |
5 u + 140 |
5 u |
| Change 1 |
- 1 u - 28 |
+ 1 u + 28 |
| After 1 |
4 u + 112 |
6 u + 28 |
| Change 2 |
+ 3 u + 14 |
- 3 u - 14 |
| After 2 |
7 u + 126 |
3 u + 14 |
20% =
20100 =
1520% x 140
=
20100 x 140
= 28
50% x 28
=
50100 x 28
= 14
50% x 6 u
=
50100 x 6 u
= 3 u
Bobby had 365 more pens than Peter in the end. If another 365 pens are given to Peter, both will have the same number of pens.
7 u + 126 = 3 u + 14 + 365
7 u - 3 u = 14 + 365 - 126
11 u = 253
1 u = 253 ÷ 11 = 23
Number of Bobby's pens at first
= 5 u + 140
= 5 x 23 + 140
= 115 + 140
= 255
Answer: 255
