Ethan has 10% as many coins as Ben. If Ethan gives away 25% of the coins and Ben gives away 40% of his coins, they will have 243 coins altogether. How many coins do the two of them have?
| |
Ethan |
Ben |
Total |
Comparing Ethan
and Ben at first |
1x4 =
4 u |
10x4 =
40 u |
|
| Before |
4x1 =
4 u |
5x8 =
40 u |
|
| Change |
- 1x1 =
- 1 u |
- 2x8 =
- 16 u |
|
| After |
3x1 =
3 u |
3x8 =
24 u |
243 |
10% =
10100 =
110 25% =
25100 =
14 40% =
40100 =
25 The number of coins that Ethan has at first is repeated. Make the number of coins that Ethan has the same. LCM of 1 and 4 is 4 u.
The number of coins that Ben has at first is repeated. Make the number of coins that Ben has the same. LCM of 10 and 5 is 40 u.
Number of coins in the end
= 3 u + 24 u
= 27 u
27 u = 243
1 u = 243 ÷ 27 = 9
Total number of coins that the two of them have
= 4 u + 40 u
= 44 u
= 44 x 9
= 396
Answer(s): 396
