The number of $5, $20 and $50 notes in a piggy bank is in the ratio of 8 : 2 : 9. The notes are worth $3710 altogether. Find the total number of $20 and $50 notes.
| |
$5 |
$20 |
$50 |
Total |
| Number |
8 u |
2 u |
9 u |
|
| Value |
$5 |
$20 |
$50 |
|
| Total value |
40 u |
40 u |
450 u |
$3710 |
Total value of $5, $20 and $50 notes
= 40 u + 40 u + 450 u
= 530 u
530 u = 3710
1 u = 3710 ÷ 530 = 7
Number of $20 and $50 notes
= 2 u + 9 u
= 11 u
= 11 x 7
= 77
Answer(s): 77
