x Turn on thread page Beta
 You are Here: Home >< Maths

# Combinations watch

1. A team of 5 managers is to be selected from a group of 10 managers. 5 from company A, 3 from company B and 2 from company C. In how many ways can this be done of the team must contain at least one manager from every company.

Feels so easy but it doesnt work out, right answer should be 175.
2. That answer doesn't seem very likely to me, unless order is important.
3. That would take alot of calculations.

Are you sure that answer is correct?
4. Isn't it

5C1 x 3C1 x 2C1 = 30

multiplied by 7C2 = 21

=630

That's what I'd read from the question anyways. Are you sure the whole question is included above?
5. Agreed.
6. (Original post by tengil)
Feels so easy but it doesnt work out, right answer should be 175.
Yep, comes to 175.

You need to consider the various cases of how the team of 5 is composed.

For example, one case would be 3 from A, 1 from B and 1 from C.
How many ways can this be done? 5C3 X 3C1 X 2C1 = 60.

There are 4 other cases to consider.

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: February 1, 2010
Today on TSR

### Been caught plagiarising...

...for the 2nd time this year

### Mum says she'll curse me if I don't go to uni

Discussions on TSR

• Latest
Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams

## Groups associated with this forum:

View associated groups
Discussions on TSR

• Latest

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE