Unit 2 · Number Theory

Four Pizzas — Quoc vs Amina

Lesson 10 of 18

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Convert everything to fifths: Amina = 4/5, Fred = 6/5, Sally = 3/5. Sum = 13/5. Quoc = 4 − 13/5 = 20/5 − 13/5 = 7/5. Quoc − Amina = 7/5 − 4/5 = 3/5.

Chapters

0:00Introduction
0:23The Question
0:58Summing the pizza eaten by friends
1:29Calculating Quoc's share
1:55Determining "how much more"
2:23Exam strategy — parsing the target question keywords
2:58Confirming the final option

Question

Quoc bought 4 pizzas to share with Amina, Fred and Sally.

Amina ate 45\frac{4}{5} of a pizza.

Fred ate 1151\frac{1}{5} pizzas.

Sally ate 35\frac{3}{5} of a pizza.

Quoc ate all of the pizza that was left.

How much more pizza did Quoc eat than Amina?

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