Answer: A) 5100 sq.m Explanation: Let the breadth of floor be 'b' m. Then, length of the floor is 'l = (b + 25)' Area of the rectangular floor = l x b = (b + 25) × b According to the question, (b + 15) (b + 8) = (b + 25) × b b2 + 8b + 15b + 120 = b2 + 25b 2b = 120 b = 60 m. l = b + 25 = 60 + 25 = 85 m.   Area of the floor = 85 × 60 = 5100 sq.m.

Answer: B) 37.5 Explanation: Angle between hands of a clock   When the minute hand is behind the hour hand, the angle between the two hands at M minutes past H 'o clock   => 30H-M5+M2 degrees   Here H = 4, M = 15 and the minute hand is behind the hour hand.   Hence the angle    = 30[4-(15/5)]+15/2 = 30(1)+7.5 = 37.5 degrees

Answer: B) 40 Explanation: The third proportional of two numbers p and q is defined to be that number r such that p : q = q : r.   Here, required third proportional of 10 & 20, and let it be 'a' => 10 : 20 = 20 : a 10a = 20 x 20 => a = 40   Hence, third proportional of 10 & 20 is 40.

Answer: C) 16:5 Explanation: Area of a square SxS = 1024 => S = 32 cmLength of the rectangle = 32x2 cm = 64 cmBreadth of the rectangle = 32 - 12 = 20 cmRequired ratio = 64 : 20 = 16 : 5

Answer: C) 4/9 Explanation: Number of white marbles = 4 Number of Black marbles = 5 Total number of marbles = 9 Number of ways, two marbles picked randomly = 9C2 Now, the required probability of picked marbles are to be of same color = 4C2/9C2  +  5C2/9C2 = 1/6 + 5/18 = 4/9.

Answer: C) 6 hrs Explanation: Suppose A, B and C take x, x/2 and x/3 respectively to finish the work.  Then, (1/x + 2/x + 3/x) = 1/2  => 6/x = 1/2      => x = 12  So, B takes 6 hours to finish the work.

Answer: D) 15.25 yrs Explanation: Total ages of 80 boys = 15 x 80 = 1200 yrs.Total age of 16 boys = 15 x 16 = 240 yrsTotal age of 25 boys = 14 x 25 = 350 yrs.Average age of remaining boys = 1200 - (240+350) / 80 - (25+15) = 610/41 = 15.25 yrs.

Answer: B) 33.33% Explanation: % Decrease in Width = 50150x100   = 33.33%