George has 30% as many coins as Simon. If George gives away 20% of the coins and Simon gives away 60% of his coins, they will have 320 coins altogether. How many coins do the two of them have?
| |
George |
Simon |
Total |
Comparing George
and Simon at first |
3x5 =
15 u |
10x5 =
50 u |
|
| Before |
5x3 =
15 u |
5x10 =
50 u |
|
| Change |
- 1x3 =
- 3 u |
- 3x10 =
- 30 u |
|
| After |
4x3 =
12 u |
2x10 =
20 u |
320 |
30% =
30100 =
310 20% =
20100 =
15 60% =
60100 =
35 The number of coins that George has at first is repeated. Make the number of coins that George has the same. LCM of 3 and 5 is 15 u.
The number of coins that Simon has at first is repeated. Make the number of coins that Simon has the same. LCM of 10 and 5 is 50 u.
Number of coins in the end
= 12 u + 20 u
= 32 u
32 u = 320
1 u = 320 ÷ 32 = 10
Total number of coins that the two of them have
= 15 u + 50 u
= 65 u
= 65 x 10
= 650
Answer(s): 650
