Advance Math Model Questions Set 2 Practice Questions Answers Test with Solutions & More Shortcuts

Question : 21

There are 6 different letters and 6 correspondingly addressed envelopes. If the letters are randomly put in the envelopes, what is the probability that exactly 5 letters go into the correctly addressed envelopes ?

a) $1/6$

b) $1/2$

c) Zero

d) $5/6$

Question : 22

One bag contains 4 white balls and 2 black balls. Another bag contains 3 white balls and 5 black balls. If one ball is drawn from each bag, determine the probability that one ball is white and another is black.

a) $5/24$

b) $7/24$

c) $6/24$

d) $13/24$

Question : 23

The probability that the 13th day of a randomly chosen month is a Friday, is

a) $1/7$

b) $1/{84}$

c) $1/{12}$

d) $1/{13}$

Question : 24

Three Englishmen and three Frenchmen work for the same company. Each of them knows a secret not known to others. They need to exchange these secrets over person-to-person phone calls so that eventually each person knows all six secrets. None of the Frenchmen knows English, and only one Englishman knows French. What is the minimum number of phone calls needed for the above purpose?

a) 10

b) 9

c) 5

d) 15

Question : 25

A programmer noted the results of attempting to run 20 programs. The results showed that 2 programs ran correctly in the first attempt, 7 ran correctly in the second attempt, 5 ran correctly in the third attempt, 4 ran correctly in the fourth attempt and 2 ran correctly in the fifth attempt. What is the probability that his next programme will run correctly on the third run ?

a) $1/3$

b) $1/6$

c) $1/4$

d) $1/5$