[Ques]: A train running at the speed of 60 km/hr crosses a pole in 9 sec. What is the length of the train?
Options:
(A) 118
(B) 150
(C) 277
(D) 258
(E) 191
*Ans*: (B)
--CoT--: Speed = 60 * 5/18 = 50/3 m/sec
Length of the train = speed * time = 50/3 * 9 = 150 m

[Ques]: The average age of a class of 32 students is 16 yrs. if the teacher's age is also included, the average increases by one year. Find the age of the teacher
Options:
(A) 34 Years
(B) 37 Years
(C) 49 Years
(D) 51 Years
(E) 57 Years
*Ans*: (C)
--CoT--: Total age of students is 32X16 = 512 Years
Total age inclusive of teacher = 33X (16+1) = 561
So, Teacher's age is 561-512 = 49 Yrs
There is a shortcut for these type of problems
Teacher's age is 16+(33X1) = 49 Years

[Ques]: In one hour, a boat goes 11 km/hr along the stream and 5 km/hr against the stream. The speed of the boat in still water (in km/hr) is:
Options:
(A) 3
(B) 4
(C) 5
(D) 8
(E) 9
*Ans*: (D)
--CoT--: Speed in still water = (11 + 5)/2 kmph = 8 kmph.

[Ques]: Find the average of the series : 312, 162, 132, 147 and 122?
Options:
(A) 170
(B) 175
(C) 180
(D) 185
(E) 195
*Ans*: (B)
--CoT--: Average = (312 + 162 + 132 + 147+ 122)/5 = 875/5 = 175