45 of Ken's savings comprised of 20-cent coins and 50-cent coins. Ken used some 20-cent coins to purchase a kitchen set. The number of 50-cent coins left was 40% more than the number of 20-cent coins left. Given that Ken had 40 more 50-cent coins than 20-cent coins left in the end, find the amount of money Ken spent on the kitchen set.
|
20-cent coins |
50-cent coins |
Before |
4x7 = 28 u |
1x7 = 7 u |
Change |
- 23 u |
|
After |
5x1 = 5 u |
7x1 = 7 u |
Fraction of Ken's savings that comprised of 50-cent coins
= 1 -
45=
15Number of 50-cents coins in the end in percentage
= 100% + 40%
= 140%
140% =
140100 =
75Number of 50-cent coins remains unchanged. Make the number of 50-cent coins the same. LCM of 1 and 7 is 7.
Number of more 50-cent coins than 20-cent coins
= 7 u - 5 u
= 2 u
2 u = 40
1 u = 40 ÷ 2 = 20
Number of 20-cent coins spent on the kitchen set
= 28 u - 5 u
= 23 u
= 23 x 20
= 460
Amount that Ken spent on the kitchen set
= 460 x 0.2
= $92
Answer(s): $92