Unit 6 · Algebra

Wed=$30, Fri=$80, x=$9 — What Is Thursday?

Lesson 11 of 12

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Cho's money box is empty on Monday morning. By Wednesday she has $30, by Friday she has $80. She saves the same amount on Tuesday, Wednesday and Friday. The twist: Thursday's deposit is an unusual large number ($41) — not one of the equal amounts. Students must first find the equal daily amount from the Wed total, then use the Fri total to isolate Thursday.

Chapters

0:00Introduction
0:23The Question
1:09Finding the Daily Savings Amount (Tuesday & Wednesday)
1:41Calculating the Total Deposited Before Friday
2:04Isolating Thursday's Deposit
2:28Confirming the Selection
2:49Correct answer

Question

Cho saves money by putting it in a money box.

At the start of Monday, the box is empty.

At the end of Monday, the box contains $12. At the end of Wednesday, the box contains $30. At the end of Friday, the box contains $80.

She puts in the same amount of money on each of Tuesday, Wednesday and Friday.

How much money does she put in on Thursday?

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