Problem 1
<h3>Answer: 3 slices</h3>
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Explanation:
1/4 = 0.25
She eats 25% of a pizza in 12 minutes
We can form the ratio 0.25/12
This ratio is then set equal to x/18. The value of x represents what proportion of the pizza is eaten after 18 minutes.
Solve for x
0.25/12 = x/18
0.25*18 = 12x ..... cross multiply
4.5 = 12x
12x = 4.5
x = 4.5/12
x = 0.375
x = 375/1000
x = (125*3)/(125*8)
x = 3/8
She ate 3/8 of the whole pizza in 18 minutes.
There are 8 slices in a full pizza, so (3/8)*8 = 3 means that she ate 3 slices.
Or you could say "eating 3 slices out of 8 total means she ate 3/8 of the full pizza".
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Problem 2
<h3>Answer:
5/8</h3>
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Explanation:
We'll use the same idea as before. Though now we're setting 0.25/12 equal to x/30
Solving for x leads to...
0.25/12 = x/30
0.25*30 = 12x
7.5 = 12x
12x = 7.5
x = 7.5/12
x = 0.625
x = 625/1000
x = (125*5)/(125*8)
x = 5/8
She will eat 5/8 of the pizza in 30 minutes.
