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Q:

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

king of heart is:

A) 2/13	B) 1/13
C) 1/26	D) 1/52

Answer & Explanation Answer: C) 1/26

Explanation:

Here, n(S) = 52.

Let E = event of getting a queen of club or a king of heart.

Then, n(E) = 2.

P(E) =n(E)/n(S)=2/52=1/26.

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Q:

A can run 22.5 m while B runs 25 m. In a kilometre race B beats A by:

A) 100 m	B) 75 m
C) 25 m	D) 50m

Answer & Explanation Answer: A) 100 m

Explanation:

When B runs 25 m, A runs 45/2 m

When B runs 1000 m, A runs (45/2*1/25*1000)m = 900 m.

B beats A by 100 m.

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Filed Under: Races and Games

Q:

In a 200 metres race A beats B by 35 m or 7 seconds. A's time over the course is:

A) 40 sec	B) 47sec
C) 33sec	D) none of these

Answer & Explanation Answer: C) 33sec

Explanation:

B runs 35 m in 7 sec.

B covers 200 m in (7/35*200) = 40 sec.

B's time over the course = 40 sec.

A's time over the course (40 - 7) sec = 33 sec.

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Q:

In a game of 100 points, A can give B 20 points and C 28 points. Then, B can give C:

A) 8 points	B) 10 points
C) 14points	D) 40points

Answer & Explanation Answer: B) 10 points

Explanation:

A : B = 100 : 80.

A : C = 100 : 72.

B:C = B/A*A/C = 80/10*100/72 = 10/9 = 100/90 = 100:90

B can give C 10 points

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Q:

Two dice are tossed. The probability that the total score is a prime number is:

A) 5/12	B) 1/6
C) 1/2	D) 7/9

Answer & Explanation Answer: A) 5/12

Explanation:

Clearly, n(S) = (6 x 6) = 36.

Let E = Event that the sum is a prime number.

Then E= { (1, 1), (1, 2), (1, 4), (1, 6), (2, 1), (2, 3), (2, 5), (3, 2), (3, 4), (4, 1), (4,3),(5, 2), (5, 6), (6, 1), (6, 5) }

n(E) = 15.

P(E) = n(E)/n(S) = 15/36 = 5/12.

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Q:

In 100 m race, A covers the distance in 36 seconds and B in 45 seconds. In this race A beats B by:

A) 20m	B) 25m
C) 22.5m	D) 9m

Answer & Explanation Answer: A) 20m

Explanation:

Distance covered by B in 9 sec. = (100/45)*9m = 20m

A beats B by 20 metres.

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Filed Under: Races and Games

Q:

In a race of 200 m, A can beat B by 31 m and C by 18 m. In a race of 350 m, C will beat B by:

A) 22.75 m	B) 25 m
C) 19.5 m	D) 18.5 m

Answer & Explanation Answer: B) 25 m

Explanation:

A : B = 200 : 169.

A : C = 200 : 182.

C/B = (C/A*A/B) = (182/200*200/169) = 182:169

When C covers 182 m, B covers 169 m.

When C covers 350 m, B covers (169/180*350)m = 325 m

Therefore, C beats B by (350 - 325) m = 25 m.

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Q:

From a pack of 52 cards, two cards are drawn together at random. What is the probability of both the cards being kings?

A) 1/15	B) 1/221
C) 25/57	D) 35/256

Answer & Explanation Answer: B) 1/221

Explanation:

Let S be the sample space

Then, n(S) = $52 C_{2}$ = 1326.

Let E = event of getting 2 kings out of 4.

n(E) = $\frac{52 * 51}{2 * 1}$ = 6.

$4 C_{2}$

=> $\frac{4 * 3}{2 * 1}$

$P (E) = \frac{n (E)}{n (S)} = \frac{6}{1326} = \frac{1}{221}$

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Filed Under: Probability

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