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

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

tens digit of (Z - 91) is 3

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Community Manager
Posts: 1048
Joined: Mon Aug 17, 2009 3:26 amFollowed by: 27 members
Location: India
Thanked: 51 times
GMAT Score:670
by arora007 » Tue Jul 06, 2010 8:20 am
If Z is a three-digit positive integer, what is the value of the tens digit of Z ?

1. The tens digit of (Z - 91) is 3
2. The units digit of (Z + 9) is 5

OA is C

from gmatclub
https://www.skiponemeal.org/
https://twitter.com/skiponemeal
Few things are impossible to diligence & skill.Great works are performed not by strength,but by perseverance

pm me if you find junk/spam/abusive language, Lets keep our community clean!!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Data Sufficiency |
User avatar
Master | Next Rank: 500 Posts
Posts: 392
Joined: Sun May 16, 2010 2:42 amFollowed by: 10 members
Location: Bangalore, India
Thanked: 116 times
GMAT Score:770

by albatross86 » Tue Jul 06, 2010 8:37 am
Z is a 3-digit positive integer. What is the tens digit of Z?

1. Tens digit of Z - 91 = 3

Let's say Z - 91 = 130 => Z = 221
Z - 91 = 239 => Z = 330

Ten's digit is different in both cases.
INSUFFICIENT

2. Units digit of Z + 9 = 5

Let's say Z + 9 = 135 => Z = 126
Z + 9 = 145 => Z = 136

Ten's digit is different in both cases.
INSUFFICIENT

Both 1 and 2 together:

Now from 2, we saw that the units digit of Z must be 6. (In order that Z + 9 has units digit 5)

Z - 91 has ten's digit 3. In order to get units digit of Z as 6, (Z - 91) must have units digit of 5, so that when 91 is added you get the 6 you need.

egs: Z - 91 = 235 => Z = 326
Z - 91 = 435 => Z = 526

i.e. The units digit MUST be 6 and thus the ten's digit of Z MUST be 2 to satisfy statement 1.

SUFFICIENT

Pick C.
~Abhay

Believe those who are seeking the truth. Doubt those who find it. -- Andre Gide
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1