Hey!
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Let's Solve A:
1/2 = 0.5
0.5 + 0.30 = 0.80
a = 0.80
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Let's Solve B:
3/4 = 0.75
0.10 + 0.75 = 0.85
b = 0.85
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Let's Solve C:
1/3 ≈ 0.33
0.33 + 0.50 = 0.83
c = 0.83
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Let's Solve D:
1/3 ≈ 0.33
0.33 + 0.40 = 0.73
d = 0.73
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Answer:
By solving each equation we can see that option A has the lowest value!
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Hope This Helped! Good Luck!