Charlie, Harry and Tom had a total of 531 stamps at first. After a week, the number of Charlie's stamps became 3 times the number of stamps he had at first. The number of Harry's stamps decreased by 431. Tom had half as many stamps as he had at first. In the end, the three boys had the same number of stamps.
- How many stamps did Tom have at first?
- What was the total number of stamps that the three boys had in the end?
|
Charlie |
Harry |
Tom |
Total |
Before |
1 u |
3 u + 431 |
6 u |
|
Change |
x 3 |
- 431 |
x 12 |
|
After |
3 u |
3 u |
3 u |
9 u |
(a)
Total number of stamps at first
=
1 u + 3 u + 431 + 6 u
= 10 u + 431
10 u + 431 = 53110 u = 531 - 43110 u = 100
1 u = 100 ÷ 10 = 10 Number of stamps that Tom had at first
= 3 u ÷
12= 3 u x
21= 6 u = 6 x 10 = 60(b)Total number of stamps that the three boys had at the end = 9 u = 9 x 10 = 90 Answer(s): (a) 60; (b) 90