GATE Practice Question and Answer
8Q: The third proportional to 9 and 12 is ? 2857 05b5cc6e9e4d2b4197774ede8
5b5cc6e9e4d2b4197774ede8- 114false
- 216true
- 318false
- 420false
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Answer : 2. "16"
Explanation :
Answer: B) 16 Explanation: Let the third proportion to 9 & 12 be 'x'. => 9:12 = 12 :p => p = 12x12/9 = 16.
Q: A man saves 20% of his monthly salary. If an account of dearness of things he is to increase his monthly expenses by 15%, he is only able to save Rs. 400 per month. What is his monthly salary ? 2857 05b5cc6e1e4d2b4197774ebf2
5b5cc6e1e4d2b4197774ebf2- 1Rs. 6000false
- 2Rs. 4500false
- 3Rs. 5000true
- 4Rs. 6500false
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Answer : 3. "Rs. 5000"
Explanation :
Answer: C) Rs. 5000 Explanation: Income = Rs. 100 Expenditure = Rs. 80 Savings = Rs. 20 Present Expenditure 80x(15/100) = Rs. 12 = 80 + 12 = Rs. 92 Present Savings = 100 – 92 = Rs. 8 100 ------ 8? --------- 400 => 5000 His salary = Rs. 5000
Q: A train for Fathehpur leaves for every 2 hrs 30 min from Agra station. An announcement was made that train left 37 mins ago and next train comes at 17:00hrs. At what time was the announcement made ? 2856 05b5cc715e4d2b4197774f445
5b5cc715e4d2b4197774f445- 115:07 hrstrue
- 215:20 hrsfalse
- 315:05 hrsfalse
- 415:00 hrsfalse
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Answer : 1. "15:07 hrs"
Explanation :
Answer: A) 15:07 hrs Explanation: Next train comes at 17:00 hrs.So, last train will be = 17:00hrs - 2:30hrs= 14:30hrsAnnouncement made after 37 min of the last train.S0, 14:30hrs + 00:37 min= 15:07 hrs.
Q: A sold an article to B at 40% profit and B sold it to C at 50% profit, then what will be profit percent with respect to A ? 2856 05b5cc6e9e4d2b4197774ee3c
5b5cc6e9e4d2b4197774ee3c- 197 %false
- 2110 %true
- 3135 %false
- 4115 %false
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Answer : 2. "110 %"
Explanation :
Answer: B) 110 % Explanation: % Profit with respect to A = 40 + 50 + (40 x 50)/100 = 90 + 20 = 110 %.
Q: A motorboat can go 10 miles downstream on a river in 20 min. It takes 30 min for this boat to go back at the same 10 miles. Find the speed of the current ? 2852 05b5cc6bfe4d2b4197774da29
5b5cc6bfe4d2b4197774da29- 18 m/hfalse
- 25 m/htrue
- 37 m/hfalse
- 46 m/hfalse
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Answer : 2. "5 m/h"
Explanation :
Answer: B) 5 m/h Explanation: As the distance travelled is constant, the time taken is inversely proportional to speed. Let 'u' be the speed of the current and 'v' be the speed of the boat. Speed of the boat downstream = v + u & upstream = v - u => v+u/v-u = 30/20 => v/u = 5 => v = 5u => v + u = 6u = 10/20/60 miles/hr => 6u = 30 m/h => u = 5 m/h
Q: The top and bottom of a tower were seen to be at angles of depression 30° and 60° from the top of a hill of height 100 m. Find the height of the tower ? 2850 15b5cc72ce4d2b4197774f79c
5b5cc72ce4d2b4197774f79c- 142.2 mtsfalse
- 233.45 mtsfalse
- 366.6 mtstrue
- 458.78 mtsfalse
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Answer : 3. "66.6 mts"
Explanation :
Answer: C) 66.6 mts Explanation: From above diagramAC represents the hill and DE represents the tower Given that AC = 100 m angleXAD = angleADB = 30° (∵ AX || BD ) angleXAE = angleAEC = 60° (∵ AX || CE) Let DE = h Then, BC = DE = h, AB = (100-h) (∵ AC=100 and BC = h), BD = CE tan 60°=AC/CE => √3 = 100/CE =>CE = 100/√3 ----- (1) tan 30° = AB/BD => 1/√3 = 100−h/BD => BD = 100−h(√3)∵ BD = CE and Substitute the value of CE from equation 1 100/√3 = 100−h(√3) => h = 66.66 mts The height of the tower = 66.66 mts.
Q: Which of the following is not soluble in water? 2847 05b5cc690e4d2b4197774c422
5b5cc690e4d2b4197774c422- 1copper(II) hydroxidetrue
- 2sodium chloridefalse
- 3silver nitratefalse
- 4potassium sulfatefalse
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Answer : 1. "copper(II) hydroxide"
Explanation :
Answer: A) copper(II) hydroxide Explanation: Sodium chloride: The solubility rules tell you that all halides are soluble with the exception of those formed with siver, mercury, and lead ions. Since this is not the case here, sodium chloride will be soluble. Silver nitrate: It is soluble because all nitrates are soluble, without exception. Potassium sulfate: It is soluble because all sulfates are soluble with the exception of those formed with silver, calcium, barium, mercury, lead, and strontium ions. Copper (II) hydroxyde: It is insoluble because all hydroxides are insoluble with the exception of those formed with alkali metal ions and barium.
Q: A train sets off at 3 p.m. at the speed of 70 kmph. Another train starts at 4:30 p.m. in the same direction at the rate of 85 kmph. At what time the trains will meet ? 2846 05b5cc6e7e4d2b4197774ed79
5b5cc6e7e4d2b4197774ed79- 110:10 pmfalse
- 29:50 pmfalse
- 311:30 pmtrue
- 410:30 pmfalse
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Answer : 3. "11:30 pm"
Explanation :
Answer: C) 11:30 pm Explanation: Distance = 70 x 1 ½ = 105 km Relative Speed = 85 – 70 = 15 Time = 105/15 = 7 hrs 4:30 + 7 hrs = 11.30 p.m.