question: Dacid obtained 76, 65, 82, 67 and 85 marks (out of 100) in English, Mathematics, Physics, Chemistry and Biology. What are his average marks?
Options:
(A) 75
(B) 45
(C) 23
(D) 28
(E) 96
answer: Stream of consciousness: Average = (76 + 65 + 82 + 67 + 85)/5 = 375/5 = 75. The answer is (A).

q: What is the difference between 80% of 170 and 35% of 300.
Options:
(A) 30
(B) 29
(C) 37
(D) 36
(E) 31
a: Stream of consciousness: (80/100) * 170 (35/100) * 300
136 - 105 = 31 The answer is (E).

question: A box contains nine bulbs out of which 4 are defective. If four bulbs are chosen at random, find the probability that all the four bulbs are defective.
Options:
(A) 62/63
(B) 125/126
(C) 1/63
(D) 1/42
(E) 1/126
answer: Stream of consciousness: Answer: Option E
Out of nine, five are good and four are defective. Required probability = c/c = 1/126 The answer is (E).

q: The average of seven numbers is 4. The average of first three numbers is 2 and the average of last three numbers is 6. What is the middle number?
Options:
(A) 3
(B) 4
(C) 6
(D) 7
(E) 8
a: Stream of consciousness: The total of seven numbers = 7X4 = 28
The total of first 3 and last 3 numbers is = 3 X 2+3 X 6 = 24
So, the middle number is (28 - 24 ) = 4 The answer is (B).

question: How many two-digit numbers satisfy this property.: The last digit (unit's digit) of the square of the two-digit number is 8 ?
Options:
(A) 1
(B) 2
(C) 3
(D) 4
(E) none of these
answer: Stream of consciousness: A number ending in 8 can never be a perfect squar The answer is (E).

question: In May Mrs Lee's earnings were 60 percent of the Lee family's total income. In June Mrs Lee earned 20 percent more than in May. If the rest of the family's income was the same both months, then, in June, Mrs Lee's earnings were approximately what percent of the Lee family's total income ?
Options:
(A) 64%
(B) 68%
(C) 72%
(D) 76%
(E) 80%
answer:
Stream of consciousness: Say May income = 100
L's income = 60 and rest of the family = 40
In June L's income = 60 * 120 /100 = 72
So 72 /72 + 40 = 64% The answer is (A).