The number of $5, $10 and $20 notes in a piggy bank is in the ratio of 9 : 1 : 9. The notes are worth $1880 altogether. Find the total number of $5 and $10 notes.
|
$5 |
$10 |
$20 |
Total |
Number |
9 u |
1 u |
9 u |
|
Value |
$5 |
$10 |
$20 |
|
Total value |
45 u |
10 u |
180 u |
$1880 |
Total value of $5, $10 and $20 notes
= 45 u + 10 u + 180 u
= 235 u
235 u = 1880
1 u = 1880 ÷ 235 = 8
Number of $5 and $10 notes
= 9 u + 1 u
= 10 u
= 10 x 8
= 80
Answer(s): 80