Answer: B) 2/3 hrs Explanation: Let the original speed and time is S and Tthen distance = S x TNow the speed changes to 2/3S and T is T+20As the distance is sameS x T = 2/3Sx(T+20)solving this we get t = 40 minutes =40/60 = 2/3 hour

Answer: B) 3,67,500 Explanation: Let the total population be 'p' Given ratio of male and female in a city is 7 : 8 In that percentage of children among male and female is 25% and 20% => Adults male and female % = 75% & 80% But given adult females is = 156800 => 80%(8p/15) = 156800 => 80 x 8p/15 x 100 = 156800 => p = 156800 x 15 x 100/80 x 8 => p = 367500 Therefore, the total population of the city = p = 367500

Answer: D) 253 Explanation: The first person shakes hands with 22 different people, the second person also shakes hands with 22 different people, but one of those handshakes was counted in the 22 for the first person, so the second person actually shakes hands with 21 new people. The third person, 20 people, and so on... So, 22 + 21 + 20 + 19 + 18 + 17 + 16 + 15 + 14 + 13 + 12 + 11 + 10 + 9 + 8 + 7 + 6 + 5 + 4 + 3 + 2 + 1= n(n+1)/2 = 22 x 23 /2 = 11 x 23 = 253.

Answer: C) 4312 sq.m Explanation: Let the radii of the smaller and the larger circles be 's' m and 'l' m respectively.    2πs = 264 and 2πl = 352      s = 2642π and l = 3522π    Difference between the areas =πl2-πs2      = π1762π2-1322π2    = 1762π-1322π     = (176 - 132)(176 + 132) / π     = (44 x 308) / (22/7) = 4312 sq.m

Answer: C) 47 Explanation: The next number in the series is 143 143 136 110       0    7      26 (Differences)  13 - 1 , 23 - 1, 33 - 1, 43 - 1,...Now the next number is given by110 - (43 - 1) = 110 - 63 = 47.

Answer: A) 63 and 49 Explanation: Since their HCFs are 7, numbers are divisible by 7 and are of the form 7x and 7y Difference = 14 => 7x - 7y = 14=> x - y = 2 product of numbers = product of their hcf and lcm=> 7x * 7y = 441 * 7=> x * y = 63 Now, we havex * y = 63 , x - y = 2=> x = 9 , y = 7 The numbers are 7x and 7y=> 63 and 49

Answer: D) 72 years Explanation: Let us consider Karthik as K1 and Kalyan as K2. Given k18+k1 and K2 - (K1 + 5) = 3  K2 - K1 = 8 K2 = 8 + K1 Now,  k18+k1= 45 => K1 = 32 years Therefore K2 = 40 years. K1 + K2 = 72 years.