Combination Question I don’t understand

Snickey

New member
The answer for Q 15, C is 42. But I don’t know how to get it. Plz help

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pka

Elite Member
The answer for Q 15, C is 42. But I don’t know how to get it. Plz help
There are four classical CDs. So at least three means three or four.
He selects five. So include three or four classical and two or one other.
Look at this It seems 42 is incorrect.

Romsek

Full Member
I'm seeing the answer as 66 ways.

$$\displaystyle \dbinom{4}{3}\dbinom{6}{2}+\dbinom{4}{4}\dbinom{6}{1} = 66$$

I'm with Romsek.

Jomo

Elite Member
Yeah, pka and Romsek are correct.

Snickey

New member
Oh alright, I got the same answer too. Guess Cambridge got it wrong. Thanks everyone!