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: A) Total internal reflection Explanation: A periscope is an optical instrument that uses a system of prisms, lenses, or mirrors to reflect images through a tube.       Light from a distant object strikes the top mirror and is then reflected at an angle of 90 degrees down the periscope tube. At the bottom of the periscope, the light strikes another mirror and is then reflected into the viewer’s eye.   Hence, A periscope works by the principle of Total internal reflection.

Answer: B) 20th April, Saturday Explanation: Given Today is 20th January 2017, Sunday In january, we have 31 days February - 28 days (Non leap year) March - 31 days April - 30 days => Remaining days => 31 - 20 = 11 in Jan + 28 in Feb + 31 in Mar = 11 + 28 + 31 = 70 days More 20 days to complete 90 days => upto 20th April   Therefore, after 90 days from today i.e, 20th Jan 2017 is 20th Apr 2017.   Now, the day of the week will be  90/7 => Remainder '6' As the day starts with '0' on sunday  6 => Saturday.   Required day is 20th April, Saturday.

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: C) rsurts Explanation: The series rtus/rtus/rtus/rtus. Thus, the pattern 'rtus' is repeated.

Answer: A) Rs. 1595.14 Explanation: Ratio of the share of a lady, a gents and a girl is 7 : 4 : 3No of ladies, gents and girls are 5, 3, 3Thus effective ratio of ladies, gents and girls is 7 x 5 : 4 x 3 : 3 x 3 = 35 : 12 : 9so part of gents = (12/56) x 7444 = Rs. 1595.142so part of 1 gents = 1595.142/3 = Rs. 531.71.

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: A) 20% p.a Explanation: Rs.1440 - 1200 = Rs.240 is the interest on Rs.1200 for one year. Rate of interest = (100 x 240) / (1200) = 20% p.a