K-numbers are positive integers with only 2's as their digits. For example, 2, 22, and 222 are K-numbers. The K-weight of a number n is the minimum number of K-numbers that must be added together to equal n. For example, the K-weight of 50 is 5, because 50 = 22 + 22 + 2 + 2 + 2. What is the K-weight of 650?
Options:
(A) 10
(B) 11
(C) 12
(D) 13
(E) 14
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650 = 2*222 + (22*9) + 4*2
K weight of 600 = 2 +9+2 = 13 So the answer is: (D).
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Find the invalid no.from the following series 13, 18, 25, 30, 37, 40
Options:
(A) 13
(B) 18
(C) 40
(D) 37
(E) 25
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The differences between two successive terms from the beginning are 7, 5, 7, 5, 7, 5. So, 40 is wrong. So the answer is: (C).
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A train running at the speed of 180 km/hr crosses a pole in 8 seconds. Find the length of the train.
Options:
(A) 150
(B) 88
(C) 480
(D) 288
(E) 400
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Speed = 180*(5/18) m/sec = 50 m/sec
Length of Train (Distance) = Speed * Time
50 *8 = 400 meter So the answer is: (E).
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