Answer: D) 3 Explanation: Given teacher drinks 9 ltrLet number of boys be 'A'.Let number of girls be 'B'.Boy drinks 7 ltr and girl drinks 4 ltrAfter class total water consumed = 42 ltrThen,9 + 7A + 4B = 42=> 7A + 4B = 33By trial and error method,The only integers which satisfy the equation is A = 3 and B = 3Therefore, number of girls in the class = 3.

Answer: A) 74 Explanation: Number of runs scored more to increse the ratio by 1 is 26 - 14 = 12To raise the average by one (from 14 to 15), he scored 12 more than the existing average.Therefore, to raise the average by five (from 14 to 19), he should score 12 x 5 = 60 more than the existing average. Thus he should score 14 + 60 = 74.

Answer: B) 7/15 Explanation: Given total students in the class = 60Students who are taking Economics = 24 andStudents who are taking Calculus = 32Students who are taking both subjects = 60-(24 + 32) = 60 - 56 = 4Students who are taking calculus only = 32 - 4 = 28probability that a randomly chosen student from this group is taking only the Calculus class = 28/60 = 7/15.

Answer: B) 60 yrs Explanation: Let the Father be x years when he died Average Age 10 years ago be A Total Age 10 years ago = 6*A Total Age after 10 years(Just before father's Death) = 6A + 6*10 = 6A + 60 Father Died and Baby was born => the Total number of people in the family is Same (6) Baby born today so age of baby = 0 (6A +60 - x)/6 = 6A/6 => A + 10 -(x/6) = A => x/6 = 10 => x = 60 Therefore we can conclude that the father was 60 years old when he died.

Answer: C) 35 days Explanation: Distance d = 1200kmlet S be the speed he walks 15 hours a day(i.e 24 - 9)so totally he walks for 70 x 15 = 1050hrs. S = 1200/1050 => 120/105 = 24/21 => 8/7kmph given 1 1/2 of previous speedso 3/2 * 8/7= 24/14 = 12/7 New speed = 12/7kmph Now he rests 10 hrs a day that means he walks 14 hrs a day. time = 840 x 7 /12 => 490 hrs=> 490/14 = 35 days So he will take 35 days to cover 840 km.

Answer: D) 18.75 % Explanation: Given,S.I = 3 Principal Amount=> 3A = A x 16 x R/100By solving, we get => R = 18.75%

Answer: B) 50 Explanation: Sony and her brother's age sum is 31Let Sony's mother's age be 'x'.Now the conditions given for both of their ages related to their mom is1/5(x-15) + 3/5(x-10) = 31x-15 + 3x-30 = 1554x-45 = 1554x = 200x = 50So, Mother's age = 50. Cross verification : 15 years ago age = 35 => Sony age = 710 years ago age = 40 => bro age = 24 Sum = 24 + 7 = 31.

Answer: B) 2 Explanation: Given that x = 2+ 223 + 213   So x - 2 = 223 + 213   Now cubing on both sides, we get     => x3-8-6x2+12x = 4 + 2 + 6(x-2)   Therefore, x3-6x2+6x = -6 + 8 = 2