59 of Henry's savings comprised of 20-cent coins and 10-cent coins. Henry used some 20-cent coins to purchase a mini plane. The number of 10-cent coins left was 50% more than the number of 20-cent coins left. Given that Henry had 40 more 10-cent coins than 20-cent coins left in the end, find the amount of money Henry spent on the mini plane.
|
20-cent coins |
10-cent coins |
Before |
5x3 = 15 u |
4x3 = 12 u |
Change |
- 7 u |
|
After |
2x4 = 8 u |
3x4 = 12 u |
Fraction of Henry's savings that comprised of 10-cent coins
= 1 -
59=
49Number of 10-cents coins in the end in percentage
= 100% + 50%
= 150%
150% =
150100 =
32Number of 10-cent coins remains unchanged. Make the number of 10-cent coins the same. LCM of 4 and 3 is 12.
Number of more 10-cent coins than 20-cent coins
= 12 u - 8 u
= 4 u
4 u = 40
1 u = 40 ÷ 4 = 10
Number of 20-cent coins spent on the mini plane
= 15 u - 8 u
= 7 u
= 7 x 10
= 70
Amount that Henry spent on the mini plane
= 70 x 0.2
= $14
Answer(s): $14