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

Redeem

time year

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Legendary Member
Posts: 1022
Joined: Mon Jul 20, 2009 11:49 pm
Location: Gandhinagar
Thanked: 41 times
Followed by:2 members

time year

by shashank.ism » Tue Feb 09, 2010 1:12 pm
How many years in the 18th century had no such day that satisfied yy = mm × dd?


20
23
18
21
19
My Websites:
www.mba.webmaggu.com - India's social Network for MBA Aspirants

www.deal.webmaggu.com -India's online discount, coupon, free stuff informer.

www.dictionary.webmaggu.com - A compact free online dictionary with images.

Nothing is Impossible, even Impossible says I'm possible.
Top
Source: — Problem Solving |
User avatar
Legendary Member
Posts: 777
Joined: Fri Jan 01, 2010 4:02 am
Location: Mumbai, India
Thanked: 117 times
Followed by:47 members

by komal » Wed Feb 17, 2010 4:40 am
shashank.ism wrote:How many years in the 18th century had no such day that satisfied yy = mm × dd?


20
23
18
21
19
We have to find two digit numbers 'yy' such that they are prime numbers greater than 31. There are 14 prime numbers
greater than 31 and less than 100. There are 6 more cases:
a. The second multiples of 37, 41, 43 and 49 will give us 4 cases.
b. The second multiple of 29 and 31 will give us two more
cases since if 'yy' = 58 or 62, in those year the month of
February will have only 28 days.
So, the total number of cases = 14 + 4 + 2 = 20.
Option (1) is the correct choice.
Top
Post new topic Post Reply
• Page 1 of 1