3 part ratio and dividing up amounts
Ratios are used to divide a large amount up. The best way to tackle these are
Work out 1 part
by adding all the ratios
Example 1
If `$6.00` is divided between three people in the ratio Karen 4: Alice 5: Brenda 6 what do they each get?
So the ratio is `4:5:6`
Add the ratio `=4+5+6=15` parts in all
Now work out `1` part
(see our section on percentages for full explanation)
`15` parts `=$6.00`
`1` part `=x`
Now put the divide sign in
`15/1=($6.00)/x`
Rearrange
`x=($6.00times1)/15`
`x=$0.40`
Therefore
| Karen 4 | `=4times$0.40=` | `$1.60` |
| Alice 5 | `=5times$0.40=` | `$2.00` |
| Brenda 6 | `=6times$0.40=` | `$2.40` |
| Total | `$6.00` |
Example 2
The ratio of adults to children in a school bingo is 4 to 1. The ratio of adults to pensioners is 4 to 3. If there are 96 people in total how many people are there of each group?
So the ratio is `=4` Adults to every `1` child to every `3` pensioners
`4:1:3`
Add the ratio `=4+1+3=8` parts
Now work out `1` part
(see our section on percentages for full explanation)
`8` parts `=96` people
`1` part `=x`
Now put the divide sign in
`8/1=96/x`
Rearrange
`x=(96times1)/8`
`x=12`
Therefore
| Adults 4 | `=12times4=` | `48` |
| Children 1 | `=12times1=` | `12` |
| Pensioners 3 | `=12times3=` | `36` |
| Total | `96` |
