GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 16 Feb 2019, 18:07

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

## Events & Promotions

###### Events & Promotions in February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
• ### Free GMAT Algebra Webinar

February 17, 2019

February 17, 2019

07:00 AM PST

09:00 AM PST

Attend this Free Algebra Webinar and learn how to master Inequalities and Absolute Value problems on GMAT.
• ### Free GMAT Strategy Webinar

February 16, 2019

February 16, 2019

07:00 AM PST

09:00 AM PST

Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT.

# A is the product of the first 100 multiples of 8.

Author Message
TAGS:

### Hide Tags

Director
Joined: 18 Jul 2018
Posts: 670
Location: India
Concentration: Finance, Marketing
WE: Engineering (Energy and Utilities)
A is the product of the first 100 multiples of 8.  [#permalink]

### Show Tags

29 Sep 2018, 18:18
3
00:00

Difficulty:

55% (hard)

Question Stats:

56% (01:47) correct 44% (02:24) wrong based on 37 sessions

### HideShow timer Statistics

A is the product of the first 100 multiples of 8. How many zeros would be there at the end of A?

a) 10
b) 11
c) 12
d) 24
e) 25

_________________

Press +1 Kudo If my post helps!

Math Expert
Joined: 02 Aug 2009
Posts: 7334
Re: A is the product of the first 100 multiples of 8.  [#permalink]

### Show Tags

29 Sep 2018, 18:43
Afc0892 wrote:
A is the product of the first 100 multiples of 8. How many zeros would be there at the end of A?

a) 10
b) 11
c) 12
d) 24
e) 25

So $$8*(8*2)*(8*3)*(8*4).....(8*99)(8*100)=8^{100}*(1*2*3..99*100)=8^{100}*100!$$

So zeroes would depend on numbers of 5s in 100! = $$\frac{100}{5}\frac{100}{5^2}=20+4=24$$

So D
_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html
4) Base while finding % increase and % decrease : https://gmatclub.com/forum/percentage-increase-decrease-what-should-be-the-denominator-287528.html

GMAT Expert

SVP
Joined: 12 Dec 2016
Posts: 1592
Location: United States
GMAT 1: 700 Q49 V33
GPA: 3.64
Re: A is the product of the first 100 multiples of 8.  [#permalink]

### Show Tags

29 Sep 2018, 19:48
this math problem is a common pattern in gmat.

Here, there is a minor error of the question. That is, 0 can be the multiple of 8. I believe that there should be a modification on this question.

The answer is simple itself. A = 100! * 8^100. We look for the number of factors 5 => D is the answer
Re: A is the product of the first 100 multiples of 8.   [#permalink] 29 Sep 2018, 19:48
Display posts from previous: Sort by