Answer: A) 2520 Explanation: The number of ways of arranging n beads in a necklace is (n-1)!2=(8-1)!2=7!2 = 2520  (since n = 8)

Answer: D) 12% p.a. Explanation: If the interest earned is 25% more than the earlier interest then the rate of interest also should be 25% higher than the earlier rate. Let the earlier rate of interest be x%. Now it will be (x + 3)% % increase = (x + 3) - x/x * 100 = 25=> x = 12%

Answer: B) 2 : 3 : 4 Explanation: Seats for Mathematics, Physics and Biology in a school are in the ratio 5 : 7 : 8. Seats for Mathematics, Physics and Biology in a school are 5x, 7x and 8x. There is a proposal to increase these seats by 40%, 50% and 75% respectively. Then Seats for Mathematics, Physics and Biology in a school will be 1.4 X 5x, 1.5 X 7x and 1.75 X 8x and ratio will be 7 : 10.5 : 14  => 2:3:4.

Answer: C) 11:30 pm Explanation: Distance = 70 x 1 ½ = 105 km Relative Speed = 85 – 70 = 15 Time = 105/15 = 7 hrs 4:30 + 7 hrs = 11.30 p.m.

Answer: B) 60 Explanation: Let the numbers be 3x, 4x, 5x.   Then, their L.C.M = 60x.   So, 60x=3600 or x=60.   Therefore,  The numbers are (3 x 60), (4 x 60), (5 x 60).   Hence,required H.C.F=60

Answer: C) 4 Explanation: Given that 3x-y=27, 3x+y=243 ⇒3x-y =33 , 3x+y=35  => x-y=3, x+y=5  => x = 4

Answer: B) 165 Explanation: The given series follow the rule that : Multiplying consecutive prime numbers2,3,5,7,11,13,17,19....2x3 = 63x5 = 155x7 = 357x11 = 7711x13 = 14313x17 = 221So, the wrong term is 165.

Answer: C) 1/6 Explanation: Given X can do in 10 days  => 1 day work of X = 1/10   Y can do in 15 days  => 1 day work of Y = 1/15   1day work of (X + Y) = 1/10 + 1/15 = 1/6   Given they are hired for 5 days  => 5 days work of (X + Y) = 5 x 1/6 = 5/6  Therefore, Unfinished work = 1 - 5/6 = 1/6