PSLE Sam saved a total of $95 in coins in his coin box.
18 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 twenty-cent coins. How many coins did Sam save in his coin box altogether?
|
One-dollar |
Ten-cent |
Twenty-cent |
Total |
Comparison between the number of 3 types of coins |
1x4 4 u |
7x4 28 u |
8x4 32 u
|
Comparison between the number of one-dollar and ten-cent coins |
4x1 |
1x1 |
|
|
Number |
4 u |
1 u |
27 u |
32 u |
Value |
1 |
0.1 |
0.2 |
|
Number x value |
4 u |
0.1 u |
5.4 u |
9.5 u |
Number of $1 coins is the repeated identity.
Make the number of $1 coins the same.
LCM of 1 and 4 = 4
Total value of coins = 9.5 u
9.5 u = 95
1 u = 95 ÷ 9.5 = 10
Total number of coins
= 4 u + 1 u + 27 u
= 32 u
= 32 x 10
= 320
Answer(s): 320