Question

Mia bought 10 1/9 lb of flour, used 2 3/4 lb making cakes, used some more for bread, and had 3 5/6 lb left when she was done. How much was used for baking bread?

Answer 1

`3 19/36` lb

Explanation:

I'm reading this to say that:

• Mia bought `10 1/9` lb of flour
• She used `2 3/4` lb making cakes
• She used some more to make bread
• She had `3 5/6` lb left when she was done

We can find the amount used in making bread by taking what she started with and subtracting what we know she used for the cakes and what she ended with - that will give us the amount used for bread:

`10 1/9-2 3/4-3 5/6`

I'm going to put these into improper form for ease:

`91/9-11/4-23/6`

Now we need a common denominator. If we look at the prime factors of each of the denominators:

`9=3xx3`
`4=2xx2`
`6=2xx3`

And so we need two 2s and two 3s:

`2xx2xx3xx3=36`

`91/9(1)-11/4(1)-23/6(1)`

`91/9(4/4)-11/4(9/9)-23/6(6/6)`

`364/36-99/36-138/36=127/36=3 19/36` lb