BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
Live EA class + 6 months of EA OnDemand
  • Expert-led weekly online sessions
  • EA Masterclass access between classes
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

130-point score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

A = (1 + 1/3)(1 + 1/3^2)(1 + 1/3^4)(1 + 1/3^8). What is the value of 1 - 2/

Expert replies
by Max@Math Revolution » Wed Apr 22, 2020 7:04 am

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty

[GMAT math practice question]

A = (1 + 1/3)(1 + 1/3^2)(1 + 1/3^4)(1 + 1/3^8). What is the value of 1 - 2/3A?

A. 1
B. 3
C. 1/3
D. 1/3^16
E. 1/3^20
Join the discussion
Source: — Problem Solving |

=>

2/3A = (1 - 1/3)(1 + 1/3)(1 + 1/3^2)(1 + 1/3^4)(1 + 1/3^8) = (1-1/3^2)(1+1/3^2)(1+1/3^4)(1+1/3^8)
= (1-1/3^4)(1+1/3^4)(1+1/3^8)
= (1-1/3^8)(1+1/3^8)
= 1-1/3^16

Thus, we have 1 - 2/3A = 1 – (1-1/3^16) = 1/3^16.

Therefore, D is the answer.
Answer: D
Join the discussion

$$A=\left(1+\frac{1}{3}\right)\left(1+\frac{1}{3^2}\right)\left(1+\frac{1}{3^4}\right)\left(1+\frac{1}{3^8}\right)$$
$$A=\left(\frac{3+1}{3}\right)\left(\frac{3^2+1}{3^2}\right)\left(\frac{3^4+1}{3^4}\right)\left(\frac{3^8+1}{3^8}\right)$$
$$A=\left(\frac{3}{3}+\frac{1}{3}\right)\left(\frac{3^2}{3^2}+\frac{1}{3^2}\right)\left(\frac{3^4}{34}+\frac{1}{3^4}\right)\left(\frac{3^8}{3^8}+\frac{1}{3^8}\right)$$
$$A=\left(\frac{1}{3}\right)\left(\frac{1}{3^2}\right)\left(\frac{1}{3^4}\right)\left(\frac{1}{3^8}\right)$$
$$A=\left(\frac{1}{3^{1+2+4+8}}\right)\ =\frac{1}{3^{15}}$$
$$Therefore,\ 1-\frac{2}{3}A$$
$$Expres\sin g\ \frac{2}{3}\ in\ form\ of\ \ \frac{1}{3}$$
$$1-\left(1-\frac{1}{3}\right)A\ \ \left(because\ \frac{1}{1}-\frac{1}{3}=\frac{2}{3}\right)$$
$$Since\ A=\frac{1}{3^{15}}$$
$$=>\ 1-1+\frac{1}{3}\left(\frac{1}{3^{15}}\right)$$
$$=\ \frac{1}{3}\cdot\frac{1}{3^{15}}=\frac{1}{3^{15+1}}=\frac{1}{3^{16}}$$
Answer = D
Join the discussion