How many pupils altogether said that cola was their favourite drink?

Question

James asked 60 pupils which drink they liked best from cola, milk and water

32 boys were included in that survey.

12 of the boys said that cola was their favourite

4 boys liked water best and 9 girls liked water best.

21 pupils altogether said that milk was their preferred drink

 

How many pupils altogether said cola was their favourite drink?

Answer 1

Start by making a chart.  We know that there are 32 boys out of 60 students, so 60-32=28.  That means there are 28 girls.  Fill these values into the chart.  Fill in the 12 boys who liked cola, the 4 boys that liked water, the 9 girls who liked water.

 

        Gender          Cola          milk          water          total

        BOYS               12                             4              32

        Girls                                                 9              28

Looking at the table now you can fill in how many boys liked milk.  If there are 32 boys total and 4 liked water and 12 liked cola, subtract 32-4-12=16.  Therefore, 16 boys liked milk.  

 

Gender           Cola           milk       water       total
BOYS              12              16            4           32
Girls                                                 9           28

So if 21 total students liked milk and 16 of those are boys, then the other 5 must be girls:  21-16=5.  Fill this into the chart.

Gender          Cola          milk        water       total
BOYS              12            16             4           32
Girls                                 5             9           28

We know that there is a total of 28 girls.  If 5 like milk and 9 like water, then 14 must like cola (28-5-9=14).  Fill this into the chart.

Gender        Cola           milk      water          total
BOYS           12              16          4               32
Girls            14               5           9               28

The answer would be the 12 boys who like cola plus the 14 girls who like cola, so the total number of pupils who like cola would be 12+14=26.

26 students like cola the best