Qualification > Math

S1 and S2 DOUBTS HERE!!!!

<< < (72/73) > >>

LekhB:
A commuter, who caught the same rain to work everyday, kept a recod over six months and found that the train was late on 49 days out of a total of 126 working days. Use a binomial probability model to estimate the probability that, in five day working week, the train will be late exactly 3 times. State briefly, giving reasons, whether a binomial model is likely to be a satisfactory or unsatisfactory mathematical model in this situation.

astarmathsandphysics:
p=49/126=7/18
P(Late 3 times)=5C3*(7/18)^3*(11/18)^2=0.2196
not suitable cos of strikes etc (in UK at least)

SauD~:
Can anyone explain me about permutation? With few examples?
Thanks,

astarmathsandphysics:
I can explain 2000 times today
See the first two videos here
http://theeducationchannel.info/videos/18/A-Level-Maths-S1/most_recent/all_time/

polltery:
A box contains 300 discs of different colours. There are 100 pink discs, 100 blue discs and 100 orange
discs. The discs of each colour are numbered from 0 to 99. Five discs are selected at random, one at
a time, with replacement. Find

(ii) the probability that exactly 2 discs with numbers ending in a 6 are selected, [3]

The marking Scheme says:
P(2 end in 6) = (1/10)2 × (9/10)3 × 5C2 =0.0729

My doubt is..
How on earth is prob success is 1/10???!
for a single disc to be numbered 6.. i am getting 1/100

Navigation

[0] Message Index

[#] Next page

[*] Previous page