PSLE Pierre saved a total of $128 in coins in his coin box.
512 of all the coins saved were one-dollar coins. There were 4 times as many one-dollar coins as ten-cent coins. The remaining coins were fifty-cent coins. How many coins did Pierre save in his coin box altogether?
|
One-dollar |
Ten-cent |
Fifty-cent |
Total |
Comparison between the number of 3 types of coins |
5x4 20 u |
7x4 28 u |
12x4 48 u
|
Comparison between the number of one-dollar and ten-cent coins |
4x5 |
1x5 |
|
|
Number |
20 u |
5 u |
23 u |
48 u |
Value |
1 |
0.1 |
0.5 |
|
Number x value |
20 u |
0.5 u |
11.5 u |
32 u |
Number of $1 coins is the repeated identity.
Make the number of $1 coins the same.
LCM of 5 and 4 = 20
Total value of coins = 32 u
32 u = 128
1 u = 128 ÷ 32 = 4
Total number of coins
= 20 u + 5 u + 23 u
= 48 u
= 48 x 4
= 192
Answer(s): 192