89 of Julian's savings comprised of 5-cent coins and 20-cent coins. Julian used some 5-cent coins to purchase a marble. The number of 20-cent coins left was 40% more than the number of 5-cent coins left. Given that Julian had 40 more 20-cent coins than 5-cent coins left in the end, find the amount of money Julian spent on the marble.
|
5-cent coins |
20-cent coins |
Before |
8x7 = 56 u |
1x7 = 7 u |
Change |
- 51 u |
|
After |
5x1 = 5 u |
7x1 = 7 u |
Fraction of Julian's savings that comprised of 20-cent coins
= 1 -
89=
19Number of 20-cents coins in the end in percentage
= 100% + 40%
= 140%
140% =
140100 =
75Number of 20-cent coins remains unchanged. Make the number of 20-cent coins the same. LCM of 1 and 7 is 7.
Number of more 20-cent coins than 5-cent coins
= 7 u - 5 u
= 2 u
2 u = 40
1 u = 40 ÷ 2 = 20
Number of 5-cent coins spent on the marble
= 56 u - 5 u
= 51 u
= 51 x 20
= 1020
Amount that Julian spent on the marble
= 1020 x 0.05
= $51
Answer(s): $51