q: A certain car uses 12 gallons of gasoline in traveling 300 miles. In order for the car to travel the same distance using 10 gallons of gasoline, by how many miles per gallon must the car's gas mileage be increased?
Options:
(A) 2
(B) 4
(C) 5
(D) 8
(E) 10
a: Stream of consciousness: 300/10 = 30. The difference is 30 - 25 = 5. The answer is (C).

question: There are 12 person among whom 2 are brother. The total no.of ways in which these persons can be seated around a round table so that exactly 1 person sit between the brothers, is equal to?
Options:
(A) 9!*2!
(B) 7!*2!
(C) 6!*1!
(D) 2!*1!
(E) 5!*1!
answer: Stream of consciousness: Total number of ways = 9!*2!. The answer is (A).

q: 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) 29 Years
(B) 32 Years
(C) 37 Years
(D) 49 Years
(E) 50 Years
a: Stream of consciousness: 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 The answer is (D).

question: How many numbers can be made with digits 0, 7, 8 which are greater than 0 and less than a million?
Options:
(A) 496
(B) 486
(C) 1084
(D) 728
(E) 628
answer: Stream of consciousness: The number of single digit numbers = 2
The number of 2 digit numbers = 2 3 = 6
The number of 3 digit numbers = 2 3 3 = 18
The number of 4 digit numbers = 2 3 3 3 = 54
The number of 5 digit numbers = 2 3 3 3 3 = 162
The number of 6 digit numbers = 2 3 3 3 3 3 = 486
Therefore, the total numbers = 728 The answer is (D).

q: A train of 25 carriages, each of 60 meters length, when an engine also of 60 meters length is running at a speed of 60 kmph. In what time will the train cross a bridge 1.5 km long?
Options:
(A) 2 mins 14 sec
(B) 2 mins 34 sec
(C) 180 sec
(D) 4 mins 54 sec
(E) 2 mins 44 sec
a: Stream of consciousness: D = 25 * 60 + 1500 = 3000 m
T = 3000/60 * 18/5 = 180 se The answer is (C).

q: The average of first 10 even numbers is?
Options:
(A) 19
(B) 18
(C) 16
(D) 11
(E) 17
a:
Stream of consciousness: Sum of 10 even numbers = 10 * 11 = 110
Average = 110/10 = 11 The answer is (D).