The number of $5, $10 and $20 notes in a piggy bank is in the ratio of 4 : 3 : 3. The notes are worth $550 altogether. Find the total number of $10 and $20 notes.
|
$5 |
$10 |
$20 |
Total |
Number |
4 u |
3 u |
3 u |
|
Value |
$5 |
$10 |
$20 |
|
Total value |
20 u |
30 u |
60 u |
$550 |
Total value of $5, $10 and $20 notes
= 20 u + 30 u + 60 u
= 110 u
110 u = 550
1 u = 550 ÷ 110 = 5
Number of $10 and $20 notes
= 3 u + 3 u
= 6 u
= 6 x 5
= 30
Answer(s): 30