Susan baked a total of 68 chocolate muffins and banana muffins. She sold 1/4 of the chocolate muffins and 1/3 of the banana muffins. How many chocolate muffins did Susan bake if she sold a total of 20 muffins?
Please help to solve the above question using model methods.
Thank you.
mr.tan
Yellow blocks represent banana. Blue blocks represent chocolate. 1/3 banana and 1/4 chocolate sold is represented by top row. So 1 yellow and 1 blue block sums to 20. That means 2nd and 3rd row are also 20 and 20. So last blue block is 68 - 20 - 20 - 20 = 8. So total chocolate muffins baked is 4 x 8 = 32. Check: Number of banana muffins = 68 - 32 = 36. Sold 1/3 x 36 = 12 banana. And 12 banana + 8 chocolate = 20 sold.
sushi88
Chocolate muffins Banana muffins
[ ——————-u———————][——————(68-u)————————]
1/4 choc muffins sold and 1/3 banana muffins sold = 20 muffin sold
(1/4)(u) + (1/3) (68-u) = 20 { x 12 on both sides}
3u + 272 -4u = 240
u = 272-240 = 32
Hence chocolate muffins baked are 32.
