physics chemistry maths science forums
become expert I help I sign up I login
refer a friend - earn nickels!!   
 advanced
 
Home
Ask & Discuss Questions
Study Material
Experts Zone
Hang Out!

Ask & Discuss Questions with Community & Experts

Moderation Team
 90 chars left    advanced
Ask iit jee aieee pet cbse icse state board community Community Discussion Question: question
Forum Index -> Algebra like the article? email it to a friend.  
Author Message
man111 (42)

Scorching goIITian

Olaaa!! Perrrfect answer. 6  [12 rates]

man111's Avatar

total posts: 266    
offline Offline

(1)  find the no. of zeros in the products 11*22*33*44*55*66*77*88.............................9898*9999*100100 is


ans=1200


1300


1050


none of these.

    
akhil_o (2704)

Blazing goIITian

Olaaa!! Perrrfect answer. 434  [701 rates]

akhil_o's Avatar

total posts: 1451    
offline Offline

count the number of 0s is to count power of 10 in the product


so we count the powers of 5 and 2


55,1010,155....100100


contain 5,10,15...and so on powers of 5


also 2525,5050,7575,100100 contain powers of 52 so we have to count twice


so power of 5


=(5+10+15+..100)+25+50+75+100


=1050+250=1300


note dat since power of 2 is higher, limiting power is power of 5


so answer is 1300


" Always remember money isn't everything but make sure you have made a lot of it before talking such nonsense!"
- Bill Gates
 this reply: 12 points  (with Olaaa!! Perrrfect answer.   in 3 votes )   [?]
 
You have to be logged on to rate
  
akhil_o (2704)

Blazing goIITian

Olaaa!! Perrrfect answer. 434  [701 rates]

akhil_o's Avatar

total posts: 1451    
offline Offline

count the number of 0s is to count power of 10 in the product


so we count the powers of 5 and 2


55,1010,155....100100


contain 5,10,15...and so on powers of 5


also 2525,5050,7575,100100 contain powers of 52 so we have to count twice


so power of 5


=(5+10+15+..100)+25+50+75+100


=1050+250=1300


note dat since power of 2 is higher, limiting power is power of 5


so answer is 1300


" Always remember money isn't everything but make sure you have made a lot of it before talking such nonsense!"
- Bill Gates
 this reply: 2 points  (with Olaaa!! Perrrfect answer.   in 1 votes )   [?]
 
You have to be logged on to rate
  
 
Forum Index -> Algebra
Go to:   

Top Offers for goIITians
Correspondence Courses
Brilliant Tutorials
Narayana Institute
Aakash Institute
Classroom/Crash Courses
Narayana - Kota , Delhi , Others
Brilliant Tutorials - Class , Crash
Aakash Institute - Medical , Engg
Online Test Series
Brilliant Tutorials
Narayana Institute
Aakash Institute
Mahesh Tutorials
AMITY      Sri Chaitanya