Rationale: Speed = 27 * 5/18 = 15/2 m/sec
Total distance covered = 250 + 200 = 450 m
Required time = 450 * 2/15 = 60 sec
The answer: (E)
Question: A train 250 m long is running at a speed of 27 km/hr. In what time will it pass a bridge 200 m long?
Options:
(A) 40
(B) 45
(C) 50
(D) 55
(E) 60
Reasoning: Total age of students is 40X15 = 600 Years
Total age inclusive of teacher = 41X (15+1) = 656
So, Teacher's age is 656-600 = 56 Yrs
There is a shortcut for these type of problems
Teacher's age is 15+(41X1) = 56 Years
Ans: (B)
Question: The average age of a class of 40 students is 15 yrs. if the teacher's age is also included, the average increases by one year. Find the age of the teacher
Options:
(A) 30 Years
(B) 56 Years
(C) 32 Years
(D) 34 Years
(E) 49 Years
Rationale: 1/2:1/2:1/4 = 2:2:1
1/5*1000 = 200
400-200 = 200
The answer: (A)
Question: Rs. 1000 is divided into three parts A, B and C. How much A is more than C if their ratio is 1/2:1/2:1/4?
Options:
(A) 200
(B) 992
(C) 772
(D) 552
(E) 312
Reasoning: Speed downstream = 90 + 20 = 110 kmph
Speed upstream = 90 - 20 = 70 kmph
Ans: (B)
Question: The speed of a boat in still water is 90kmph and the speed of the current is 20kmph. Find the speed downstream and upstream?
Options:
(A) 40, 68 kmph
(B) 110, 70 kmph
(C) 90, 60 kmph
(D) 40, 60 kmph
(E) 20, 60 kmph
Rationale: Money paid in cash = Rs. 2500
Balance payment = (40000- 2500) = Rs. 37500.
The answer: (D)
Question: The price of a T.V. set worth Rs. 40000 is to be paid in 20 installments of Rs. 2500 each. If the rate of interest be 6% per annum, and the first installment be paid at the time of purchase, then the value of the last installment covering the interest as well will be?
Options:
(A) 29997
(B) 28088
(C) 27098
(D) 37500
(E) 2799
Rationale: The correct answer should not take the form: 4x + 1. Hence, it is
The answer: (E)
Question: People standing in a straight line are wearing alternating colored shirts. The pattern of shirts begins with red, followed by green, blue, and yellow. This pattern continues (red, green, blue, and yellow) until it ends with a red shirt. If there are more than 4 people in line, which of the following cannot be the number of people in the line?
Options:
(A) 17
(B) 37
(C) 49
(D) 61
(E) 72