HELP! GCSE Maths question - Independent Probability

stamina9008

Hi, this question is killing me because the methods to answer (B) and (C) are not explained in my textbooks, which, frankly...is more than annoying!!!!!
So please, can anyone try to explain B and C to me???
Ive tried searching online, but i just find the usual Independent Probability stuff, and not the ways in which i am to approach B and C.
Here it is...

John has end-of-term tests in Maths, English, Science and Geography.
The probability he passes Maths is 2/3. The probability he passes Science is 3/4. The probability he passes English is 2/5 and the probability he passes Geography is 1/2. What is the probability of him passing:

A. All four subjects? I assume this is P=(M,E,S,G) which = 1/10??

But these...

B. ONLY mathematics?

C. ATLEAST one subject

ps - Please, my damn revision book doesnt tell you how to answer B or C, so i imagine that they want you to use logic? Lol, maybe thats not me, i dunno..

But help if you can,

Cheers.

lesalanos

Its been a while since I went to school but

for b I think that it is

pass maths and fail all others =

2/3 x 1/4 x 3/5 x 1/2 = 1/20

not sure on c, will have to think about that

alanrowell

For C you work out the probability of failing all subjects then subtract that from 1.

1/3 x 1/4 x 3/5 x 1/2 = 3/120 = 0.025 = 0.975

victor2

I would think C is 1 (certainty) minus the probability of him failing all of the subjects. So 1-(1/3 x 1/4 x 3/5 x 1/2) = 0.975

edit:
And the probability of us both getting the same answer and being wrong....;)

closed

what's the probability of you ever needing to know this in real life?