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.

In the Land of OZ only one or two-letter words are used.

Expert replies
by swerve » Mon May 07, 2018 11:16 am

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty

In the Land of OZ, only one or two-letter words are used. The local language has 66 different letters. The parliament decided to forbid the use of the seventh letter. How many words have the people of OZ lost because of the prohibition?

A. 65
B. 66
C. 67
D. 131
E. 132

The OA is E.

Please, can anyone explain this PS question for me? I need help. I tried to solve it but I can't get the correct answer. Thanks.
Join the discussion
Source: — Problem Solving |

by Jay@ManhattanReview » Mon May 07, 2018 8:04 pm
swerve wrote:In the Land of OZ, only one or two-letter words are used. The local language has 66 different letters. The parliament decided to forbid the use of the seventh letter. How many words have the people of OZ lost because of the prohibition?

A. 65
B. 66
C. 67
D. 131
E. 132

The OA is E.

Please, can anyone explain this PS question for me? I need help. I tried to solve it but I can't get the correct answer. Thanks.
Before the prohibition:

The number of 1-letter words = 66;
The number of 2-letter words = 66*66 = 66^2

Total number of words = 66 + 66^2

After the prohibition:

The number of 1-letter words = 65;
The number of 2-letter words = 65*65 = 65^2

Total number of words = 65 + 65^2

The number of words lost = [66 + 66^2] - [65 + 65^2] = 1 + [66^2 - 65^2] = 1 + (66 - 65)(66 + 65) = 1 + 1*(131) = 1 + 131 = 132.

The correct answer: E

Hope this helps!

-Jay
_________________
Manhattan Review GMAT Prep

Locations: New York | Singapore | Doha | Lausanne | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.
Join the discussion

by Brent@GMATPrepNow » Tue May 08, 2018 8:37 am
Jay@ManhattanReview wrote:
swerve wrote:In the Land of OZ, only one or two-letter words are used. The local language has 66 different letters. The parliament decided to forbid the use of the seventh letter. How many words have the people of OZ lost because of the prohibition?

A. 65
B. 66
C. 67
D. 131
E. 132
Jay's approach (above) is exactly how I would have solved it.
The only way my approach differs is when we get to:

The number of words lost = [66 + 66²] - [65 + 65²]
At this point, we might notice that each of the 5 answer choices has a DIFFERENT UNITS DIGIT.
So, we can save some time by focusing solely on the UNITS DIGITS
For example, notice that 66² = ---6 [we need not concern ourselves with the other digits. We need only recognize that (66)(66) = some number with 6 as its units digit ]
Likewise 65² = (65)(65) = ----5

So, we get:
The number of words lost = [66 + 66²] - [65 + 65²]
= [66 + ---6] - [65 + ----5]
= (------2) - (----0)
= ------2

Since only answer choice E has a units digit of 2, the correct answer must be E

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Join the discussion

by regor60 » Tue May 08, 2018 9:01 am
Or you can focus on the words no longer permitted.

One letter word = 1 word lost

Two letter word: call first letter the forbidden letter. Then there are 65 other letters except for the forbidden one that can't be paired so 65 choices. Multiply by 2 since the forbidden letter can be swapped to the second position = 130 lost words.

Finally, recognize you can have a two letter word with both letters being forbidden = 1 lost word

Total lost words 132, E
Join the discussion

by Scott@TargetTestPrep » Wed May 09, 2018 3:51 pm
swerve wrote:In the Land of OZ, only one or two-letter words are used. The local language has 66 different letters. The parliament decided to forbid the use of the seventh letter. How many words have the people of OZ lost because of the prohibition?

A. 65
B. 66
C. 67
D. 131
E. 132
We are given that in the Land of OZ only one- or two-letter words are used. If all 66 letters can be used, then we have:

1-letter words = 66

2-letter words = 66^2

Thus, there are 66 + 66^2 words if all 66 letters can be used.

When the seventh letter is taken away, we have:

1-letter words = 65

2-letter words = 65^2

Thus, there are 65 + 65^2 words when the seventh letter is taken away.

The number of lost words is:

(66 + 66^2) - (65 + 65^2)

66 + 66^2 - 65 - 65^2

1 + 66^2 - 65^2

Noting that the expression 66^2 - 65^2 is a difference of squares, we have:

1 + (66 - 65)(66 + 65)

1 + (1)(131) = 132

Answer: E

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage
Join the discussion