Question- ( 1 to 4 )A quiz has three rounds of two questions each. In the first round each correct answers carries 20 points whereas each incorrect answer carries a penalty of 10 points. If both the questions are answered correctly a bonus of 10 points is awarded. In the second round each correct and incorrect answer carries the same number of points as in the first round. However an additional penalty of 10 points is awarded if both the questions were answered incorrectly. In the final round each correct answer carries 40 points and an incorrect one carries a penalty of 20 points.
Question- 1 If only two answers were correct what is the probability that the score would be 20?
A 1/3
B 1/2
C 0
D 2/3
E 1/6
Explanation
C (0)
There are only two ways of scoring 20 from the table viz: 50 + 10 – 40 or 10+50-40.
In both cases there are three right answers.
Question- 2 In how many ways can a score of 40 be achieved in the quiz?
A 2
B 1
C 0
D 3
E 4
Explanation
B (1)
40 can be scored by: (1)50-30 + 20 or (2) 10 + 10 + 20.
Question -3 If two answers are incorrect, the minimum possible score is?
A 60
B 50
C 40
D 70
E 80
Explanation
A (60)
The maximum Penalty for 2 incorrect answers would occur when they happen in the last
round. Hence, the score would be 50 +50 – 40 = 60.
Question- 4 What is the probability of scoring 100 in the quiz?
A 4/27
B 2/27
C 2/9
D 1/9
E 5/9
Explanation
B (2/27)
There are 3 x 3 x 3 = 27 possible scores. Out of these three there are only 2 ways of scoring 100.
Hence 2/27.
