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1/3 + 1/2 - 5/6 + 1/5 + 1/4 - 9/20 =
A) 0
B) 2/15
C) 2/5
D) 9/20
E) 5/6
Answer: A
A) 0
B) 2/15
C) 2/5
D) 9/20
E) 5/6
Answer: A
One option is to rewrite each fraction with the same denominator (a bit of work).boomgoesthegmat wrote:1/3 + 1/2 - 5/6 + 1/5 + 1/4 - 9/20 =
A) 0
B) 2/15
C) 2/5
D) 9/20
E) 5/6
Answer: A
Another option is to convert each fraction to a decimal.
To do so, we need to know some BASE CONVERSIONS.
Let's use this chart
For example, if we know that 1/7 ≈ 0.14, then 2/7 ≈ 0.28
Likewise, if 1/6 ≈ 0.17, then 5/6 ≈ 0.83 [since 5/6 = 1 - 1/6 ≈ 1 - 0.17 ≈ 0.83]
So....
1/3 + 1/2 - 5/6 + 1/5 + 1/4 - 9/20 = 0.33 + 0.5 - 0.83 + 0.2 + 0.25 - 0.45
= 0 + 0
= 0
= A
For more on converting fractions to decimals see this video: https://www.gmatprepnow.com/module/gmat ... video/1066
Cheers,
Brent
