Bright Zoom Maths

Aptitude puzzle What is the four-digit number (no zeros) in which the third digit is the number of ′wind′ the first digit is one-half of the third, the second digit is double the third and the last digit is one-half the sum of the first three? Answer: 2847 Explanation: Wind = 4 letters The third number = 4 First digit = 1 / 2 of the third digit = ( 1 / 2 ) * 4 = 2 Second digit = Double the third digit = 2 * 4 = 8 Fourth digit = 1 / 2 of the sum of first three digits = ( 1 / 2 ) * ( 2 + 8 + 4 ) = ( 1 / 2 ) * 14 = 7 Four digit number = 2847

Aptitude Solved Problems Bright Zoom Maths, 1. 36 men can complete a piece of work in 18 days. In how many days will 24 men complete the same work? Answer:  27 days Explanation: Let the required number of days be x. ⇒ Less men, More days ( ∴ Indirect propportion ) ⇒ 24 : 36 :: 18 : x ⇒ 24x = 36 * 18 x = ( 36 * 18 ) / 24 x = 9 * 3 x = 27 days ∴ 27 days to complete the work 2. In a lottery, there are 25 prizes and 10 blanks. A lottery is drawn at random. What is the probability of getting a prize? Answer:  5 / 7 Explanation: Total number of outcomes possible, n ( S ) = 25 + 10   = 35 Total number of prize, n ( E ) = 25 p ( E ) = n ( E ) / n ( S ) = 25 / 35 .  = 5 / 7 ∴ Required probability = 5 / 7 3. Three numbers are in the ratio of 2 : 3 : 4 and their L.C.M. is 360. Find their H.C.F. ? Answer:  30 Explanation: Let HCF of the numbers be x Let the numbers be 2x, 3x and 4x. LCM of 2x, 3x and 4x = 12x ⇒ 12x = 360 x = ...

Aptitude Solved Problems - Average Bright Zoom Maths, Question  : 1 The captain of a cricket team of 11 members is 28 years old and the wicket keeper is 3 years older. If the ages of these two are excluded, the average age of the remaining players is one year less than the average age of the whole team. What is the average age of the team? Answer:  25 years Explanation: Let the average age of the whole team be x years Given data, the age of captain of a cricket team = 28 years If the wicket keeper is 3 years older, Then, the age of wicket keeper = 28 + 3 = 31 If the ages of these two are excluded, the average age of the remaining players is one year less than the average age of the whole team, Then, new average ⇒ [ 11x - ( 28 + 31 ) ] / 9 = x - 1 [ 11x - 59 ] / 9 = x - 1 ( 11x - 59 ) = 9 ( x - 1 ) ( 11x - 59 ) = 9x - 9 11x - 9x = 59 - 9 2x = 50 x = 25 ∴ The average age of the whole team is 25 years. Question  : 2 Out of 9 persons, 8 persons spent R...

Aptitude puzzle Bright Zoom Maths, What is the four-digit number (no zeros) in which the third digit is the number of ′wind′ the first digit is one-half of the third, the second digit is double the third and the last digit is one-half the sum of the first three? Answer: 2847 Explanation: Wind = 4 letters The third number = 4 First digit = 1 / 2 of the third digit = ( 1 / 2 ) * 4 = 2 Second digit = Double the third digit = 2 * 4 = 8 Fourth digit = 1 / 2 of the sum of first three digits = ( 1 / 2 ) * ( 2 + 8 + 4 ) = ( 1 / 2 ) * 14 = 7 Four digit number = 2847

Aptitude puzzle Bright Zoom Maths, Question  : 1 You have a large number of friends coming over and they all get thirsty. Your first friend asks for 1 / 2 a cup of water. Your second friend asks for 1 / 4 a cup of water. Your third friend asks for 1 / 8 a cup of water, etc. How many cups of water do you need to serve your friends? Answer: One Explanation: First friend asks for 1 / 2 a cup of water Second friend asks for 1 / 4 a cup of water Third friend asks for 1 / 8 a cup of water Total cup of water = ( 1 / 2 ) + ( 1 / 4 ) + ( 1 / 8 ) + ...... [ Friends kept asking for water like this forever one cup would be enough ] Total cup of water = 1 Question  : 2 Alex is shuffling a pack of cards ( 54 cards in total ) and after some time, he takes out a joker card. Now, he splits the remaining cards into two piles. Can you find out the probability where one of the piles has a sequence of card from A to K in order? Answer: 1 / 6227020800 Explanation: N car...

Aptitude Solved Problems -  Percentage  1. Three candidates contested an election and received 1035, 6635 and 10625 votes respectively. What percentage of the total votes did the winning candidate get? Answer: 58.07 % Explanation: Given, the total number of votes polled = 1035 + 6635 + 10625 = 18295 The winning candidate got = 10625 votes To find the percentage of the total votes did the winning candidate got, Required percentage = [ ( winning candidate′s votes / total votes ) * 100 ] % = [ ( 10625 / 18295 ) * 100 ] % = 58.07 % ∴ The percentage of the total votes did the winning candidate got 58.07 % 2. Two tailors X and Y are paid a total of Rs. 880 per week by their employer. If X is paid 120 percent of the sum paid to Y, how much is Y paid per week? Answer: Rs. 400 Explanation: Let the sum paid to Y per week be Rs. z Then, z + 120 % of z = 880 z + ( 120 / 100 ) * z = 880 z + ( 6 / 5 ) z = 880 ( 5z + 6z ) / 5 = 880 11z / 5 = 880 z = ( 880 * 5 ...

Aptitude Solved Problems..! Bright Zoom Maths, Question  :1 The ratio of the number of boys and girls in a school is 7 : 8. If the percentage increase in the number of boys and girls be 10% and 30% respectively, what will be the new ratio? Answer: 77 : 104 Explanation: Originally, let the number of boys and girls in the school be 7x and 8x respectively Their increased number is  (110% of 7x) and (130% of 8x) => ( 110 / 100 ) * 7x and  ( 130 / 100 ) * 8x => ( 11 / 10 ) * 7x and ( 13 / 10 ) * 8x => ( 77 / 10 ) * x and ( 104 / 10 ) * x The required ratio  = ( 77x / 10 ) : ( 104x / 10 ) = 77x : 104x = 77 : 104 ∴ Required ratio = 77 : 104 Question  :2 2. A 200m long train is running at 54 Kmph. how much time it will take to cross a platform of 115m long? Answer: 21 sec Explanation: Total distance = Length of the train + Length of the platform = 200 m + 115 m = 315 m Speed = 54 km / hr To convert km / hr in to m / s x km / hr = x...

Data Interpretation :  Line Charts-1 Directions to Solve Study the following line graph and answer the questions. Exports from Three Companies Over the Years (in Rs. crore) 1.  For which of the following pairs of years the total exports from the three Companies together are equal? A. 1995 and 1998 B. 1996 and 1998 C. 1997 and 1998 D. 1995 and 1996 Answer:  Option  D Explanation: Total exports of the three Companies X, Y and Z together, during various years are: In 1993 = Rs. (30 + 80 + 60) crores = Rs. 170 crores. In 1994 = Rs. (60 + 40 + 90) crores = Rs. 190 crores. In 1995 = Rs. (40 + 60 + 120) crores = Rs. 220 crores. In 1996 = Rs. (70 + 60 + 90) crores = Rs. 220 crores. In 1997 = Rs. (100 + 80 + 60) crores = Rs. 240 crores. In 1998 = Rs. (50 + 100 + 80) crores = Rs. 230 crores. In 1999 = Rs. (120 + 140 + 100) crores = Rs. 360 crores. Clearly, the total exports of the three Companies X, Y and Z together are same d...