Last visit was: 13 Dec 2024, 02:46 It is currently 13 Dec 2024, 02:46
Close
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
Your Progress

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
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Close
Request Expert Reply
Confirm Cancel
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 13 Dec 2024
Posts: 97,864
Own Kudos:
685,461
 []
Given Kudos: 88,266
Products:
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 97,864
Kudos: 685,461
 []
2
Kudos
Add Kudos
12
Bookmarks
Bookmark this Post
Most Helpful Reply
avatar
aadit
Joined: 14 Apr 2015
Last visit: 12 Oct 2015
Posts: 2
Own Kudos:
7
 []
Given Kudos: 5
Posts: 2
Kudos: 7
 []
3
Kudos
Add Kudos
3
Bookmarks
Bookmark this Post
General Discussion
User avatar
mathivanan
Joined: 10 Jun 2015
Last visit: 20 Sep 2015
Posts: 85
Own Kudos:
73
 []
Posts: 85
Kudos: 73
 []
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
D3N0
Joined: 21 Jan 2015
Last visit: 13 Dec 2024
Posts: 447
Own Kudos:
Given Kudos: 107
Location: India
Concentration: Strategy, Marketing
GMAT 1: 620 Q48 V28
GMAT 2: 690 Q49 V35
WE:Sales (Consumer Packaged Goods)
Products:
GMAT 2: 690 Q49 V35
Posts: 447
Kudos: 372
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
7 points are marked on a straight line and another 8 points are marked on a second straight line with no points in common. How many triangles can be constructed with vertices from among the above points?

A. 21
B. 91
C. 168
D. 196
E. 364

Ans: E

Solution: select 2 from 8 and one from 7 + select 2 from 7 and 1 from 8
8C2*7C1 + 7C2*8C1
= 196+ 168 = 364
User avatar
AdlaT
Joined: 06 Oct 2013
Last visit: 12 May 2017
Posts: 38
Own Kudos:
146
 []
Given Kudos: 34
Posts: 38
Kudos: 146
 []
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
7 points are marked on a straight line and another 8 points are marked on a second straight line with no points in common. How many triangles can be constructed with vertices from among the above points?

A. 21
B. 91
C. 168
D. 196
E. 364

Kudos for a correct solution.

Method.1: choose 2 points from 7 points in \(7C2\) ways and 1 point from 8 points in \(8\) ways or choose 2 points from 8 points in 8C2\(\) ways and 1 point from 7 point in 7 ways.

total traingles \(7C2*8+8C2*7\).

Method.2: choose 3 points from 7 points in \(7C3\) ways or choose 3 points from 8 points in \(8C3\) ways and subtract from \(15C3\).

\(15C3-(7C3+8C3)\)
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 35,804
Own Kudos:
Posts: 35,804
Kudos: 929
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Moderator:
Math Expert
97864 posts