An equity analyst needs to select 2 stocks for the upcoming year and rank these securities in terms of their investment potential. If the analyst has narrowed down the list of potential stocks to 5, in how many ways can she choose and rank her top 2 picks?
Options:
(A) 20
(B) 30
(C) 10
(D) 40
(E) 80
Answer and stream of consciousness: (A)
Stream of consciousness: Number of ways of choosing 2 stocks = 5C2
Number of ways of ranking the chosen stocks = 2!
Hence total ways of chosing and ranking = 5C2 * 2! = 20

A can do a certain work in 12 days. B is 60% more efficient than A. How many days does B alone take to do the same job ?
Options:
(A) 19
(B) 15
(C) 16
(D) 17
(E) 18
Answer and stream of consciousness: (B)
Stream of consciousness: Ratio of time taken by A & B = 160:100 = 8:5 Suppose B alone takes x days to do the job. Then, 8:5::12:x = > 8x = 5*12 = > x = 15 days.

A class consists of 100 students, 25 of them are girls and 75 boys; 20 of them are rich and remaining poor; 20 of them are fair complexioned. The probability of selecting a fair complexioned rich girl is
Options:
(A) 1/125
(B) 1/59
(C) 1/56
(D) 1/54
(E) 1/53
Answer and stream of consciousness: (A)
Stream of consciousness: The probability of selecting girl is: 25/100 = 1/4
The probability of selecting rich is: 20/100 = 1/5
The probability of selecting fair complexioned is: 20/100 = 1/5
Three are independent;probability of rich and fair complexioned girl is:
(1/4) (1/5) (1/5) = 1/125

The average weight of 36 men is 50 kg. It was found later that the figure of 37 kg was misread as 73 kg. What is the correct average?
Options:
(A) 49 kg
(B) 51 kg
(C) 50.5 kg
(D) 51.5 kg
(E) None of these
Answer and stream of consciousness:
(A)
Stream of consciousness: Correct average = [( 50 x 36) - 73 + 37 )]/36 = 1764/36 = 49 kg.