Make the amount of money they have £100 because this makes the question easier.
Colin gets 3/10 of the money, so Colin will get £30.
After Colin has taken his share £70 will be left over.
The ratio give is 3 : 2. So 3 + 2 is equal to 5.
The amount of money left over is then divided by the ratio added in this case its 70/5.
70/5 gives us an answer of 14 .
This means that each share is equal to £14.
Emma gets the ratio of 3 so we do 3 x 14 which gives us he answer of £42.
And if we do 3 x 2 we get the answer of £28.
We then know Dave gets £26 pounds from the £100 at the start.
26/100 converted to a percentage is 26%.