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 →

zeroes in 100!

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Problem Solving |
User avatar
Senior | Next Rank: 100 Posts
Posts: 58
Joined: Thu Sep 29, 2011 5:15 amFollowed by: 1 member
Thanked: 7 times
GMAT Score:740

by kul512 » Thu Feb 23, 2012 10:08 am
Number is zeros in n is-

(n/5)+(n/25)+(n/125)...

if n=100
(100/5)+(100/25)=20+4=24

Logic is: Number of zeros means total number of 10. Total number of 10 means total number of 5 (because 2 is available in abundant :-)). To calculate the number of 5 we divide 100 by 5, first term of the above written expression. But four terms are there which have 2 five embed in them and they are 25,50,75,100 so total 4, which is second term of the above written equation.
Answer is B.
Last edited by kul512 on Thu Feb 23, 2012 5:11 pm, edited 1 time in total.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Community Manager
Posts: 1060
Joined: Fri May 13, 2011 6:46 amFollowed by: 52 members
Location: Utrecht, The Netherlands
Thanked: 318 times

by neelgandham » Thu Feb 23, 2012 1:19 pm
100! = 1*2*3*4*5*...10...15...20...25....100 = (5^n) * X, where X,n are integers

The Total number of zeroes = Total number of 5's in the product.

First method - Counting the number of 5's
5 - 1,
10 - 2,
15 - 3,
20 - 4
25(5*5) - 5,6
30 - 7,
35 - 8,
40 - 9,
45 - 10,
50(5*5*2) - 11,12,
55 - 13,
60 - 14,
65 - 15,
70 - 16,
75(5*5*3)- 17,18,
80 - 19,
85 - 20,
90 - 21,
95 - 22,
100(5*5*4) - 23,24

Total - 24

Second Method - Mentioned above by kul
Anil Gandham
Welcome to BEATtheGMAT | Photography | Getting Started | BTG Community rules | MBA Watch
Check out GMAT Prep Now's online course at https://www.gmatprepnow.com/
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1