Japheth, Seth and Tom had a total of 95 coins. The ratio of the number of coins that Seth had to the number of coins that Tom had was 4 : 7. After Japheth and Seth each gave away half of their coins, the 3 children had 72 coins left. How many coins did Seth and Tom have at first?
| |
Japheth |
Seth |
Tom |
Total |
| Before |
2 p |
4 u |
7 u |
95 |
| Change |
- 1 p |
- 2 u |
|
- 23 |
| After |
1 p |
2 u |
7 u |
72 |
Total number of coins that Japheth and Seth gave away
= 95 - 72
= 23
1 p + 2 u = 23 --- (1)
1 p + 2 u + 7 u = 72
1 p + 9 u = 72 --- (2)
(2) - (1)
(1 p + 9 u) - (1 p + 2 u) = 72 - 23
9 u - 2 u = 49
7 u = 49
1 u = 49 ÷ 7 = 7
Total number of coins that Seth and Tom had at first
= 4 u + 7 u
= 11 u
= 11 x 7
= 77
Answer(s): 77
