Rs.800 amounts to Rs.920 in 3 years at simple interest. If the interest is increased by 3%, it would amount to how much?
Options:
(A) 288
(B) 277
(C) 209
(D) 992
(E) 612
Answer and stream of consciousness: (D)
Stream of consciousness: (800*3*3)/100 = 72
920 + 72 = 992

A marble shop contains 6 blue marbles, 6 red marbles, and 6 green marbles. If 4 marbles are purchased at random from the shop, what is the probability that the 4 marbles will be the same color?
Options:
(A) 1/68
(B) 60/68
(C) 13/68
(D) 13/48
(E) 1/48
Answer and stream of consciousness: (A)
Stream of consciousness: It doesn't matter which type of card you choose, so:
Probability of choosing 1st card: 1
Probability of choosing 2nd card of the same type: 5/17
Probability of choosing 3rd card of the same type: 4/16
Probability of choosing 4th marble of the same type: 3/15
Multiply and you get 1/68

A class consists of 100 students, 30 of them are girls and 70 boys; 20 of them are rich and remaining poor; 40 of them are fair complexioned. The probability of selecting a fair complexioned rich girl is
Options:
(A) 3/125
(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: 30/100 = 3/10
The probability of selecting rich is: 20/100 = 1/5
The probability of selecting fair complexioned is: 40/100 = 2/5
Three are independent;probability of rich and fair complexioned girl is:
(3/10) (1/5) (2/5) = 3/125

Of the 50 electronics components that a factory must
manufacture, 70 percent would be most e ciently manufactured
by Machine A and the remaining 30 percent would be most
e ciently manufactured by Machine B, though either machine
could manufacture any of the 50 components. If 36 percent of
the components were manufactured by Machine A and the
remainder were manufactured by Machine B, what is the
highest possible number of components that were
manufactured by the machine that would manufacture them
the most efficiently?
Options:
(A) 30
(B) 31
(C) 32
(D) 33
(E) 34
Answer and stream of consciousness:
(D)
Stream of consciousness: # components A and B could manufacture efficiently:
A: 50*70% = 35
B: 50*30% = 15
# components A and B effectively manufacture:
A: 50*36% = 18
B: 50*64% = 32
Max. # components efficiently manufactured:
18 (from A) and 15 (from B) = 33