Bobby, Tom and Wesley had a total of 38 pens. The ratio of the number of pens that Tom had to the number of pens that Wesley had was 8 : 7. After Bobby and Tom each gave away half of their pens, the 3 children had 26 pens left. How many pens did Tom and Wesley have at first?
| |
Bobby |
Tom |
Wesley |
Total |
| Before |
2 p |
8 u |
7 u |
38 |
| Change |
- 1 p |
- 4 u |
|
- 12 |
| After |
1 p |
4 u |
7 u |
26 |
Total number of pens that Bobby and Tom gave away
= 38 - 26
= 12
1 p + 4 u = 12 --- (1)
1 p + 4 u + 7 u = 26
1 p + 11 u = 26 --- (2)
(2) - (1)
(1 p + 11 u) - (1 p + 4 u) = 26 - 12
11 u - 4 u = 14
7 u = 14
1 u = 14 ÷ 7 = 2
Total number of pens that Tom and Wesley had at first
= 8 u + 7 u
= 15 u
= 15 x 2
= 30
Answer(s): 30
