Unit 3 · Measurement and Data

$5.40 Change, Six 50c Fixed — Max 20c Coins?

Lesson 11 of 12

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About this lesson

Now for a more demanding money problem — one where the total change is fixed but the coin mix is constrained. These questions test whether you can work through the constraints in the right order rather than jumping straight to the answer.

Chapters

0:00Introduction
0:23The Question
1:09Calculating total spend and change due
1:36Deducting the fixed 50-cent coins
2:03Maximising the 20-cent coins and final selection
2:41Strategic exam tip
3:18Correct answer

Question

A juice bottle costs $2.30 and a snack bar costs $1.15.

Lily buys one juice bottle and two snack bars and pays with a $10 note.

The cashier has no $1 coins and no $2 coins, only 50-cent coins, 20-cent coins and 10-cent coins.

Lily's change contains exactly six 50-cent coins.

What is the greatest number of 20-cent coins Lily could have in her change?

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$5.40 Change, Six 50c Fixed — Max 20c Coins? | Measurement and Data | GoTestPrep