PSLE Paul saved a total of $117 in coins in his coin box.
59 of all the coins saved were one-dollar coins. There were 3 times as many one-dollar coins as twenty-cent coins. The remaining coins were fifty-cent coins. How many coins did Paul save in his coin box altogether?
|
One-dollar |
Twenty-cent |
Fifty-cent |
Total |
Comparison between the number of 3 types of coins |
5x3 15 u |
4x3 12 u |
9x3 27 u
|
Comparison between the number of one-dollar and twenty-cent coins |
3x5 |
1x5 |
|
|
Number |
15 u |
5 u |
7 u |
27 u |
Value |
1 |
0.2 |
0.5 |
|
Number x value |
15 u |
1 u |
3.5 u |
19.5 u |
Number of $1 coins is the repeated identity.
Make the number of $1 coins the same.
LCM of 5 and 3 = 15
Total value of coins = 19.5 u
19.5 u = 117
1 u = 117 ÷ 19.5 = 6
Total number of coins
= 15 u + 5 u + 7 u
= 27 u
= 27 x 6
= 162
Answer(s): 162