Question: A car finishes a journey in five hours at the speed of 100 km/hr. If the same distance is to be covered in two hours how much more speed does the car have to gain?
Options:
(A) 8 km/hr
(B) 10 km/hr
(C) 150 km/hr
(D) 16 km/hr
(E) None of these
Ans: (C)
CoT: Distance covered by the car = 100 5 = 500 km
\ Speed = 5002 = 250 km/hr
\ Speed gain = 250 100 = 150 km/hr
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Question: In how many different ways can the letters of the word 'EXTENT' be arranged?
Options:
(A) 250
(B) 180
(C) 300
(D) 310
(E) 360
Ans: (B)
CoT: Number of ways = 6!/2!2! = 6X5X4X3X2X1/2X1X2X1 = 180
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Question: The average mark obtained by 23 candidates in an examination is 45. The average of the first ten is 55 while the last eleven is 40 .The marks obtained by the 11th candidate is ?
Options:
(A) 26
(B) 45
(C) 90
(D) 80
(E) 65
Ans: (B)
CoT: It is clear that 23 x 45 = 10 x 55 + K + 11 x 40 K = 45
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