PSLE Henry saved a total of $149 in coins in his coin box.
37 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 Henry save in his coin box altogether?
|
One-dollar |
Ten-cent |
Twenty-cent |
Total |
Comparison between the number of 3 types of coins |
3x4 12 u |
4x4 16 u |
7x4 28 u
|
Comparison between the number of one-dollar and ten-cent coins |
4x3 |
1x3 |
|
|
Number |
12 u |
3 u |
13 u |
28 u |
Value |
1 |
0.1 |
0.2 |
|
Number x value |
12 u |
0.3 u |
2.6 u |
14.9 u |
Number of $1 coins is the repeated identity.
Make the number of $1 coins the same.
LCM of 3 and 4 = 12
Total value of coins = 14.9 u
14.9 u = 149
1 u = 149 ÷ 14.9 = 10
Total number of coins
= 12 u + 3 u + 13 u
= 28 u
= 28 x 10
= 280
Answer(s): 280