PSLE Julian had a total of 300 coins in his coin box.
710 of all the coins saved were one-dollar coins. There were 3 times as many one-dollar coins as fifty-cent coins. The remaining coins were twenty-cent coins. What was the total value of all the coins in his coin box?
|
One-dollar |
Fifty-cent |
Twenty-cent |
Total |
Comparison between the number of 3 types of coins |
7x3 21 u |
3x3 9 u |
10x3 30 u
|
Comparison between the number of one-dollar and fifty-cent coins |
3x7 |
1x7 |
|
|
Number |
21 u |
7 u |
2 u |
30 u |
Value |
1 |
0.5 |
0.2 |
|
Number x value |
21 u |
3.5 u |
0.4 u |
24.9 u |
Number of $1 coins is the repeated identity.
Make the number of $1 coins the same.
LCM of 7 and 3 = 21
Total number of coins = 30 u
30 u = 300
1 u = 300 ÷ 30 = 10
Total value of coins
= 21 u 3.5 u 0.4 u
= 24.9 u
= 24.9 x 10
= $249
Answer(s): $249