there are 48 counters in a bag.
There are only red counters and blue counters in the bag.
number of red counters: number of blue counters = 1:3
Ellie has to work out how many red counters are in the bag.
She says: "There are 16 red counters in the bag because one third of 48 is 16"
Is ellie correct? You must give a reason for your answer