GATE Practice Question and Answer
8Q: Whether the last number 240 in the following series is according to the remaining numbers pattern ? 2, 4, 12, 48, 240 1253 05b5cc6c0e4d2b4197774daf8
5b5cc6c0e4d2b4197774daf8- 1TRUEtrue
- 2FALSE Answer & Explanation Answer:false
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 1. "TRUE"
Explanation :
Answer: A) TRUE Explanation: The given series follows, 2 2 x 2 = 4 4 x 3 = 12 12 x 4 = 48 48 x 5 = 240.
Q: Three taps P, Q and R can fill a tank in 12 hrs, 15 hrs and 20 hrs respectively. If P is open all the time and Q and R are open for one hour each alternately, starting with Q, then the tank will be full in how many hours ? 2937 05b5cc6c0e4d2b4197774dafb
5b5cc6c0e4d2b4197774dafb- 19 hrsfalse
- 27 hrstrue
- 313 hrsfalse
- 411 hrsfalse
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 2. "7 hrs"
Explanation :
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.
Q: A student multiplied a number by 2/5 instead of 5/2. What is the percentage error in evaluation ? 1707 05b5cc6c0e4d2b4197774dae4
5b5cc6c0e4d2b4197774dae4- 152%false
- 264%false
- 384%true
- 477%false
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 3. "84%"
Explanation :
Answer: C) 84% Explanation: Let the number be 'x' Then, according to the given data, 52x-25x52xx100 = 2125x100 = 84%
Q: Crack the series missing Number Puzzle ? 1818 05b5cc6c0e4d2b4197774dad0
5b5cc6c0e4d2b4197774dad0- 1330false
- 2253false
- 3221false
- 4363true
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 4. "363"
Explanation :
Answer: D) 363 Explanation: The given numbers in the series follows a pattern that, 3 (3 x 3) + 3 = 12 (12 x 3) + 3 = 39 (39 x 3) + 3 = 120 (120 x 3) + 3 = 363.
Q: If the HCF of 210 and 55 is expressible in the form of 210 x 5 + 55P, then value of P = ? 1723 05b5cc6c0e4d2b4197774dacb
5b5cc6c0e4d2b4197774dacb- 1-23false
- 227false
- 316false
- 4-19true
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 4. "-19"
Explanation :
Answer: D) -19 Explanation: HCF of 210 and 55 is 5 Now, 210x5 + 55P = 5 => 1050 + 55P = 5 => 55P = -1045 => P = -1045/55 => P = -19.
Q: In a daily morning walk three persons step off together. their steps measure 75 cm, 80 cm and 85 cm respectively. What is the minimum distance each should walk so that thay can cover the distance in complete steps ? 1590 05b5cc6c0e4d2b4197774dabc
5b5cc6c0e4d2b4197774dabc- 1222 m 44 cmfalse
- 2204 mtrue
- 3201 m 21 cmfalse
- 4208 mfalse
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 2. "204 m"
Explanation :
Answer: B) 204 m Explanation: To find the minimum distance, we have to get the LCM of 75, 80, 85 Now, LCM of 75, 80, 85 = 5 x 15 x 16 x 17 = 20400 Hence, the minimum distance each should walk so that thay can cover the distance in complete steps = 20400 cms = 20400/100 = 204 mts.
Q: Two numbers are in the ratio 3 : 7. If 6 be added to each of them, then they are in the ratio 5 : 9. Find the numbers ? 1765 05b5cc6c0e4d2b4197774dab7
5b5cc6c0e4d2b4197774dab7- 111 & 17false
- 27 & 17false
- 39 & 21true
- 413 & 23false
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 3. "9 & 21"
Explanation :
Answer: C) 9 & 21 Explanation: Let the two numbers be x and y Given x : y = 3 : 7 .....(1) Now, x+6 : y+6 = 5 : 9 .....(2) From (1), x = 3y/7 From (2), 5y - 9x = 24 => 5y - 9(3y/7) = 24 => y = 21 => From(1), x = 9 Hence, the two numbers be 9 and 21
Q: The mean of 100 observations is 40. It is found that an observation 84 was misread as 48. Then the correct mean is ? 1667 05b5cc6c0e4d2b4197774dab2
5b5cc6c0e4d2b4197774dab2- 140.36true
- 241.24false
- 341.92false
- 442.05false
- Show AnswerHide Answer
- Workspace
- SingleChoice
Answer : 1. "40.36"
Explanation :
Answer: A) 40.36 Explanation: Given, mean of 100 observations is 40 => Total of 100 observations = 40 x 100 = 4000 84 is misread as 48 => Difference = 84 - 48 = 36 => Now, new total of 100 observations = 4000 + 36 = 4036 Correct Mean = 4036/100 = 40.36

