Will has 70% as many stamps as Tom. If Will gives away 25% of the stamps and Tom gives away 50% of his stamps, they will have 451 stamps altogether. How many stamps do the two of them have?
| |
Will |
Tom |
Total |
Comparing Will
and Tom at first |
7x4 =
28 u |
10x4 =
40 u |
|
| Before |
4x7 =
28 u |
2x20 =
40 u |
|
| Change |
- 1x7 =
- 7 u |
- 1x20 =
- 20 u |
|
| After |
3x7 =
21 u |
1x20 =
20 u |
451 |
70% =
70100 =
710 25% =
25100 =
14 50% =
50100 =
12 The number of stamps that Will has at first is repeated. Make the number of stamps that Will has the same. LCM of 7 and 4 is 28 u.
The number of stamps that Tom has at first is repeated. Make the number of stamps that Tom has the same. LCM of 10 and 2 is 40 u.
Number of stamps in the end
= 21 u + 20 u
= 41 u
41 u = 451
1 u = 451 ÷ 41 = 11
Total number of stamps that the two of them have
= 28 u + 40 u
= 68 u
= 68 x 11
= 748
Answer(s): 748
