The number of $2, $10 and $20 notes in a piggy bank is in the ratio of 8 : 5 : 4. The notes are worth $730 altogether. Find the total number of $10 and $20 notes.
| |
$2 |
$10 |
$20 |
Total |
| Number |
8 u |
5 u |
4 u |
|
| Value |
$2 |
$10 |
$20 |
|
| Total value |
16 u |
50 u |
80 u |
$730 |
Total value of $2, $10 and $20 notes
= 16 u + 50 u + 80 u
= 146 u
146 u = 730
1 u = 730 ÷ 146 = 5
Number of $10 and $20 notes
= 5 u + 4 u
= 9 u
= 9 x 5
= 45
Answer(s): 45
