4

# A speaks truth in 75% of cases and B in 80% of cases. In what percentage of cases are they likely to contradict each other, narrating the same incident

30%

35%

40%

45%

B. 35%

Let A = Event that A speaks the truth
B = Event that B speaks the truth
Then P(A) =
P(B) =
P(A-lie) =
P(B-lie) =
Now, A and B contradict each other = [A lies and B true] or [B true and B lies]
= P(A).P(B-lie) + P(A-lie).P(B)

4

# Three unbiased coins are tossed, what is the probability of getting at least 2 tails ?

$\frac{1}{3}$

$\frac{1}{6}$

$\frac{1}{2}$

$\frac{1}{8}$

4

# A box contains 20 electric bulbs, out of which 4 are defective. Two bulbs are chosen at random from this box. The probability that at least one of these is defective is

$\frac{7}{19}$

$\frac{6}{19}$

$\frac{5}{19}$

$\frac{4}{19}$

4

30%

35%

40%

45%

4

# A card is drawn from a pack of 52 cards. The probability of getting a queen of club or a king of heart is

$\frac{1}{13}$

$\frac{2}{13}$

$\frac{1}{26}$

$\frac{1}{52}$

4

# From a pack of 52 cards, two cards are drawn together, what is the probability that both the cards are kings

$\frac{2}{121}$

$\frac{2}{221}$

$\frac{1}{221}$

$\frac{1}{13}$

4

# What is the probability of getting a sum 9 from two throws of dice.

$\frac{1}{3}$

$\frac{1}{9}$

$\frac{1}{12}$

$\frac{2}{9}$

4

# In a throw of dice what is the probability of getting number greater than 5

$\frac{1}{2}$

$\frac{1}{3}$

$\frac{1}{5}$

$\frac{1}{6}$

4

# In a throw of coin what is the probability of getting tails.

1

2

$\frac{1}{2}$

0

4

# Two dice are thrown simultaneously. What is the probability of getting two numbers whose product is even ?

$\frac{3}{4}$

$\frac{1}{4}$

$\frac{7}{4}$

$\frac{1}{2}$

4

# Two unbiased coins are tossed. What is probability of getting at most one tail ?

$\frac{1}{2}$

$\frac{1}{3}$

$\frac{3}{2}$

$\frac{3}{4}$

4

# In a throw of coin what is the probability of getting head.

1

2

$\frac{1}{2}$

0

4

# Bag contain 10 back and 20 white balls, One ball is drawn at random. What is the probability that ball is white

1

$\frac{2}{3}$

$\frac{1}{3}$

$\frac{4}{3}$

4

# From a pack of 52 cards, 1 card is drawn at random. Find the probability of a face card drawn.

$\frac{4}{13}$

$\frac{1}{52}$

$\frac{1}{4}$

None of above

4

# A box contains 5 green, 4 yellow and 3 white balls. Three balls are drawn at random. What is the probability that they are not of same colour.

$\frac{52}{55}$

$\frac{3}{55}$

$\frac{41}{44}$

$\frac{3}{44}$

$\frac{2}{3}$
$\frac{8}{21}$
$\frac{3}{7}$
$\frac{9}{22}$