Anna had some coin collection.
37 of them were gold and the rest were pink. She gave away 174 of the pink coins and 30% of the gold coins. She then had
14 of her coin collection left. How many coins did Anna give away?
|
Gold |
Pink |
Total |
Total |
Before
|
3x4 = 12 u |
4x4 = 16 u |
7x4 = 28 u |
4x7 = 28 u |
Change
|
- 0.9x4 = - 3.6 u |
- 174 |
|
- 3x7 = - 21 u |
After
|
2.1x4 = 8.4 u |
16 u - 174 |
|
1x7 = 7 u |
The total number of coins that Anna had at first is repeated. Make the total number of coins at first the same. LCM 7 and 4 is 28.
Number of gold coins that Anna gave away
= 30% x 3 u
=
30100 x 3 u
= 0.9 u
3.6 u - 174 = 21 u
21 u - 3.6 u = 174
17.4 u = 174
1 u = 174 ÷ 17.4 = 10
Number of coins that Anna gave away
= 21 u
= 21 x 10
= 210
Answer(s): 210