PSLE Ryan saved a total of $51 in coins in his coin box.
112 of all the coins saved were one-dollar coins. There were 4 times as many one-dollar coins as twenty-cent coins. The remaining coins were ten-cent coins. How many coins did Ryan save in his coin box altogether?
|
One-dollar |
Twenty-cent |
Ten-cent |
Total |
Comparison between the number of 3 types of coins |
1x4 4 u |
11x4 44 u |
12x4 48 u
|
Comparison between the number of one-dollar and twenty-cent coins |
4x1 |
1x1 |
|
|
Number |
4 u |
1 u |
43 u |
48 u |
Value |
1 |
0.2 |
0.1 |
|
Number x value |
4 u |
0.2 u |
4.3 u |
8.5 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 = 8.5 u
8.5 u = 51
1 u = 51 ÷ 8.5 = 6
Total number of coins
= 4 u + 1 u + 43 u
= 48 u
= 48 x 6
= 288
Answer(s): 288