NDA/NA SOLVED PAPER 2016-I (MATHEMATICS)

Total Questions: 120

91. What is the mean deviation from the mean of the numbers 10,9, 21, 16, 24?

Correct Answer: (a) 5.2
Solution:


92. Three dice are thrown simultaneously. What is the probability that the sum on the three faces is at least 5?

Correct Answer: (b) 53/54
Solution:

93. Two independent events A and B have P(A) = 1/3 and P(B) = 3/4 What is the probability that exactly one of the two events A or B occurs?

Correct Answer: (d) 7/12
Solution:

94. A coin is tossed three times. What is the probability of getting head and tail alternately?

Correct Answer: (b) 1/4
Solution:

95. Solve the following equation

Correct Answer: (c) 1700
Solution:


96. A card is drawn from a wel-shuffled deck of 52 cards. What is the probability that it is queen of spade?

Correct Answer: (a) -1/52
Solution:

97. If two dice are thrown, then what is the probability that the sum on the two faces is greater than or equal to 4?

Correct Answer: (c) 11/12
Solution:

98. A certain type of missile hits the target with probability p = 0.3 . What is the least number of missiles should be fired so that there is at least an 80% probability that the target is hit?

Correct Answer: (a) 5
Solution:

99. For two mutually exclusive events A and B, P(A) = 0.2 and P (Ā ∩ B) = 0.3. What is P( A |(A ∪ B)) equal to?

Correct Answer: (b) 2/5
Solution:

100. What is the probability of 5 Sundays in the month of December?

Correct Answer: (c) 3/7
Solution:In month of December 31 days i.e. (28 + 3) days. In 28 days will get 4 Sundays.
If we get any Sunday in first 3 days of December than only we can get 5 Sundays in month.
n (5th Sunday) = 3  [4 weeks + 3 days]
n(5)=7
Hence prob. of 5 Sundays in month of December = 3/7.