 # 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

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

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

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