q: 4000 was divided into two parts such a way that when first part was invested at 3% and the second at 5%, the whole annual interest from both the investments is Rs.144, how much was put at 3%?
Options:
(A) 8279
(B) 2890
(C) 2800
(D) 2730
(E) 3702
a: Stream of consciousness: (x*3*1)/100 + [(4000 - x)*5*1]/100 = 144
3x/100 + 200 5x/100 = 144
2x/100 = 56 e x = 2800 The answer is (C).
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q: An analyst will recommend a combination of 3 industrial stocks, 2 transportation stocks, and 2 utility stocks. If the analyst can choose from 5 industrial stocks, 5 transportation stocks, and 3 utility stocks, how many different combinations of 7 stocks are possible?
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Options:
(A) 12
(B) 19
(C) 60
(D) 180
(E) 300
a: Stream of consciousness: 5C3 * 5C2 * 3C2 = 10*10*3 = 300. The answer is (E).
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q: There are two water tanks A and B, A is much smaller than B. While water fills at the rate of one liter every hour in A, it gets filled up like 10, 20, 40, 80, 160 in tank B. (At the end of first hour, B has 10 liters, second hour it has 20, third hour it has 40 and so on). If tank B is 1/32 filled after 21 hours, what is the total duration required to fill it completely?
Options:
(A) 22
(B) 28
(C) 269
(D) 26
(E) 82
a:
Stream of consciousness: The data related to the first tank A is not necessary. As you can see, the capacity that gets filled in the tank B after each hour is doubled. So If the tank is 1/32nd part is full after 21 hours, it is 1/16th part full after 22 hours, 1/8th part full after 23 hours, 1/4th part full after 24 hours, 1/2 full after 25 hours, completely full after 26 hours. The answer is (D).
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