The number of $20, $50 and $100 notes in a piggy bank is in the ratio of 5 : 2 : 1. The notes are worth $1800 altogether. Find the total number of $50 and $100 notes.
| |
$20 |
$50 |
$100 |
Total |
| Number |
5 u |
2 u |
1 u |
|
| Value |
$20 |
$50 |
$100 |
|
| Total value |
100 u |
100 u |
100 u |
$1800 |
Total value of $20, $50 and $100 notes
= 100 u + 100 u + 100 u
= 300 u
300 u = 1800
1 u = 1800 ÷ 300 = 6
Number of $50 and $100 notes
= 2 u + 1 u
= 3 u
= 3 x 6
= 18
Answer(s): 18
