Reasoning: (1056 / 25) gives remainder 6
19 + 6 = 23, So we need to add 19
Ans: (A)
Question: What is the least number should be added to 1056, so the sum of the number is completely divisible by 25?
Options:
(A) 19
(B) 20
(C) 32
(D) 41
(E) 53
Rationale: P(at least one red) = 1 - P(no red, so 2 blue) = 1- 2/5*1/4 = 9/10.
The answer: (C)
Question: In a jar there are 3 red gumballs and 2 blue gumballs. What is the probability of drawing at least one red gumball when drawing two consecutive balls randomly?
Options:
(A) 2/5
(B) 16/20
(C) 9/10
(D) 3/5
(E) 1/3
Reasoning: The total of seven numbers = 7X18 = 126
The total of first 3 and last 3 numbers is = 3 X 12+3 X 19 = 99
So, the middle number is (126 - 93 ) = 33
Ans: (D)
Question: The average of seven numbers is 18. The average of first three numbers is 12 and the average of last three numbers is 19. What is the middle number?
Options:
(A) 25
(B) 27
(C) 29
(D) 33
(E) 34
Rationale: 8C3 [Select any four] - 6C3 [Select all hard backs] = 36.
The answer: (A)
Question: There are 8 books in a shelf that consist of 2 paperback books and 6 hardback books. If 3 books are selected at random without replacement, how many different combinations are there that at least one paperback book is selected?
Options:
(A) 36
(B) 45
(C) 50
(D) 55
(E) 60
Reasoning: The total of seven numbers = 7X18 = 126
The total of first 3 and last 3 numbers is = 3 X 16+3 X 20 = 108
So, the middle number is (126 - 108 ) = 18
Ans: (D)
Question: The average of seven numbers is 18. The average of first three numbers is 16 and the average of last three numbers is 20. What is the middle number?
Options:
(A) 20
(B) 22
(C) 25
(D) 18
(E) 24
Reasoning: Let the time taken be = x
One way distance = 54x
Total distance traveled = 2 * 54x = 108x
Total time taken = x + 2x = 3x
Average speed = 108x/3x = 36
Ans: (C)
Question: A car traveled from San Diego to San Francisco at an average speed of 54 miles per hour. If the journey back took twice as long, what was the average speed of the trip?
Options:
(A) 24.
(B) 32.
(C) 36.
(D) 42.
(E) 44.