Answer: B) 29 yrs Explanation: Total age seven persons = (26 x 7)yearsTotal age of the first three persons and the last three persons are (19 x 3) years and (32 x 3) years respectively.Age of the person sitting in the middle of the row = 26 x 7 - 19 x 3 - 32 x 3 = 182 - 57 - 96 = 29 years.

Answer: A) Lactic acid Explanation:

Answer: D) -1 Explanation: 3, 7, 6, 5, 9, 3, 12, 1, 15, ... has two different series 1) 3, 6, 9, 12, 15..... 2) 7, 5, 3, 1, ..... -1 is the next number.

Answer: B) 7 hrs Explanation: Given, P can fill in 12 hrs Q can fill in 15 hrs R can fill in 20 hrs => Volume of tank = LCM of 12, 15, 20 = 60 lit => P alone can fill the tank in 60/12 = 5 hrs => Q alone can fill the tank in 60/15 = 4 hrs => R alone can fill the tank in 60/20 = 3 hrs Tank can be filled in the way that (P+Q) + (P+R) + (P+Q) + (P+R) + .... => Tank filled in 2 hrs = (5+4) + (5+3) = 9 + 8 = 17 lit => In 6 hrs = 17 x 6/2 = 51 lit => In 7th hr = 51 + (5+4) = 51 + 9 = 60 lit => So, total tank will be filled in 7 hrs.

Answer: A) M & N Explanation: There are 26 English Alphabets. They are:   A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z.   Therefore, from the left end the 13th letter is M and is Consonent. And from the right end the 13th letter is N and is Consonent.

Answer: A) Dennis M. Ritchie Explanation: C, an early systems programming language, was developed by Dennis Ritchie and Ken Thompson at Bell Labs between 1969 and 1973.

Answer: A) 9!/(2!)^{2}x3! Explanation: n items of which p are alike of one kind, q alike of the other, r alike of another kind and the remaining are distinct can be arranged in a row in n!/p!q!r! ways.The letter pattern 'MESMERISE' consists of 10 letters of which there are 2M's, 3E's, 2S's and 1I and 1R.Number of arrangements = 9!(2!)2×3!

Rain is what only comes down but never goes up.