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: B) 60 kms Explanation: Let 'd' be the distance and 's' be the speed and 't' be the timed=sxt45 mins = 3/4 hr and 48 mins = 4/5 hrAs distance is same in both cases;s(3/4) = (s-5)(4/5)3s/4 = (4s-20)/515s = 16s-80s = 80 km.=> d = 80 x 3/4 = 60 kms.

Answer: A) 0.0625 Explanation: 25% of 25% means   25/100 of 25/100   i.e, 1/4 of 1/4   or in other words 1/4 x 1/4=1/16   Hence, the answer is 1/16 = 0.0625.

Answer: C) Rs. 5000 Explanation: Income = Rs. 100 Expenditure = Rs. 80 Savings = Rs. 20 Present Expenditure 80x(15/100) = Rs. 12 = 80 + 12 = Rs. 92 Present Savings = 100 – 92 = Rs. 8 100 ------ 8? --------- 400 => 5000 His salary = Rs. 5000

Answer: A) 4 kmph Explanation: Let the speed of current = 'C' km/hr   Given the speed of boat in still water = 6 kmph   Let 'd' kms be the distance it covers.   According to the given data,   Boat takes thrice as much time in going the same distance against the current than going with the current   i.e, d8 - C = 3 × d8 + C   ⇒ 24 - 3C = 8 + C⇒ 4C = 16⇒ C = 4 kmph   Hence, the speed of the current C = 4 kmph.

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