The number of $2, $10 and $20 notes in a piggy bank is in the ratio of 5 : 8 : 3. The notes are worth $1800 altogether. Find the total number of $10 and $20 notes.
| |
$2 |
$10 |
$20 |
Total |
| Number |
5 u |
8 u |
3 u |
|
| Value |
$2 |
$10 |
$20 |
|
| Total value |
10 u |
80 u |
60 u |
$1800 |
Total value of $2, $10 and $20 notes
= 10 u + 80 u + 60 u
= 150 u
150 u = 1800
1 u = 1800 ÷ 150 = 12
Number of $10 and $20 notes
= 8 u + 3 u
= 11 u
= 11 x 12
= 132
Answer(s): 132
