Unit 8 · Rates and Ratios

Omid's Blocks — What Is the Final Level?

Lesson 3 of 7

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About this lesson

2 identical blocks raise a jug from 100 mL to 150 mL — a rise of 50 mL total, so 25 mL per block. 5 more blocks add 5×25=125 mL. New level = 150+125 = 275 mL. Option A (225 mL) traps students who add 125 mL to the original 100 mL instead of the current 150 mL.

Chapters

0:00Introduction
0:22The Question
1:05Calculating the Volume of the First Two Blocks
1:32Determining the Volume of a Single Block
1:56Calculating the Final Water Level
2:27Exam Strategy — The Baseline Reset Trap
3:18Confirming the Final Option

Question

Omid has a 1 litre measuring jug. It contains 100 mL of water.

He has some identical blocks. He drops two blocks into the water and they sink. The water level rises to 150 mL.

Omid drops five more blocks into the water.

What is the new water level?

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