The number of $2, $10 and $20 notes in a piggy bank is in the ratio of 9 : 9 : 5. The notes are worth $2080 altogether. Find the total number of $10 and $20 notes.
| |
$2 |
$10 |
$20 |
Total |
| Number |
9 u |
9 u |
5 u |
|
| Value |
$2 |
$10 |
$20 |
|
| Total value |
18 u |
90 u |
100 u |
$2080 |
Total value of $2, $10 and $20 notes
= 18 u + 90 u + 100 u
= 208 u
208 u = 2080
1 u = 2080 ÷ 208 = 10
Number of $10 and $20 notes
= 9 u + 5 u
= 14 u
= 14 x 10
= 140
Answer(s): 140
