Mrs Chen bought some eggs. She used 1/2 of them to make tarts and 1/4 of the remainder to make a cake. She had 9 eggs left. How many eggs did she buy?
2 Answers
She starts with 24 eggs.
Explanation:
We can work through this question, by using only fractions.
Mrs Chen used
This means she has
She uses another
Together she has used:
If
Check:
I have chosen to write this in a similar way to that used by algebra as an introduction to the methods.
Explanation:
First use
Second use
Total use is:
Therefor not used is:
But not used is 9 eggs
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But we need 1 of total count. Not
Multiply both sides by
Note that this is where the shortcut method of cross multiply comes from.
Note that