0.1 + (0.1)^2 + (0.1)^3

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0.1 + (0.1)^2 + (0.1)^3

by boomgoesthegmat » Thu Apr 28, 2016 1:38 pm
0.1 + (0.1)^2 + (0.1)^3 =

A) 0.1
B) 0.111
C) 0.1211
D) 0.2341
E) 0.3

B

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by Brent@GMATPrepNow » Thu Apr 28, 2016 2:02 pm
boomgoesthegmat wrote:0.1 + (0.1)^2 + (0.1)^3 =

A) 0.1
B) 0.111
C) 0.1211
D) 0.2341
E) 0.3

B
One approach is to convert each decimal to a fraction, and then apply the powers.
We get: 0.1 + (0.1)² + (0.1)³ = 1/10 + (1/10)² + (1/10)³
= 1/10 + 1/100 + 1/1000
= 100/1000 + 10/1000 + 1/1000 [rewrite each fraction with common denominator of 1000]
= 111/1000
= 0.111 [rewrite as decimal]

Answer: B

Related Resources
The following videos cover the concepts/strategies that are useful for answering this question:
- Introduction to fractions: https://www.gmatprepnow.com/module/gmat ... video/1065
- Conversions with fractions and decimals: https://www.gmatprepnow.com/module/gmat ... video/1066
- Operations with fractions: https://www.gmatprepnow.com/module/gmat ... video/1068

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by Matt@VeritasPrep » Thu Apr 28, 2016 2:07 pm
I'd factor:

.1 * (1 + .1 + .1*.1) =

(1/10) * (1 + 1/10 * 1/100) =

1/10 + 1/100 + 1/1000 =

.111

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by Scott@TargetTestPrep » Tue Mar 27, 2018 10:36 am
boomgoesthegmat wrote:0.1 + (0.1)^2 + (0.1)^3 =

A) 0.1
B) 0.111
C) 0.1211
D) 0.2341
E) 0.3
0.1 + (0.1)^2 + (0.1)^3 = 0.1 + 0.01 + 0.001 = 0.111

Answer: B

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