First of all work out how many tom and scott sold. tom sold 60% of 90 cookies which is 54. scott sold 2/3 of 150 cookies which is 100. altogether the three of them sold 54+100+46 cookies which is 200. Dawn sold 46 of these 200 cookies. To work out the percentage we have both the numbers to get 23 out of 100. We halved those numbers because a percentage is out of 100 we halved it to get it out of 100. so 23 out of 100 is 23% so dawn sold 23%of the cookies.
