GATE Practice Question and Answer
8Q: A box contains 4 different black balls, 3 different red balls and 5 different blue balls. In how many ways can the balls be selected if every selection must have at least 1 black ball and one red ball ? 2815 05b5cc6f4e4d2b4197774f004
5b5cc6f4e4d2b4197774f004- 124 - 1false
- 22425-1false
- 3(24-1)(23-1)25true
- 4Nonefalse
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Answer : 3. "(24-1)(23-1)25"
Explanation :
Answer: C) C Explanation: It is explicitly given that all the 4 black balls are different, all the 3 red balls are different and all the 5 blue balls are different. Hence this is a case where all are distinct objects. Initially let's find out the number of ways in which we can select the black balls. Note that at least 1 black ball must be included in each selection. Hence, we can select 1 black ball from 4 black ballsor 2 black balls from 4 black balls.or 3 black balls from 4 black balls.or 4 black balls from 4 black balls. Hence, number of ways in which we can select the black balls = 4C1 + 4C2 + 4C3 + 4C4= 24-1 ........(A) Now let's find out the number of ways in which we can select the red balls. Note that at least 1 red ball must be included in each selection. Hence, we can select 1 red ball from 3 red ballsor 2 red balls from 3 red ballsor 3 red balls from 3 red balls Hence, number of ways in which we can select the red balls= 3C1 + 3C2 + 3C3=23-1........(B) Hence, we can select 0 blue ball from 5 blue balls (i.e, do not select any blue ball. In this case, only black and red balls will be there)or 1 blue ball from 5 blue ballsor 2 blue balls from 5 blue ballsor 3 blue balls from 5 blue ballsor 4 blue balls from 5 blue ballsor 5 blue balls from 5 blue balls. Hence, number of ways in which we can select the blue balls= 5C0 + 5C1 + 5C2 + … + 5C5= 25..............(C) From (A), (B) and (C), required number of ways= 2524-123-1
Q: Read the following puzzle carefully, answer the question asked below ? Seven person K, L, M, N, O, P & Q likes seven colours. Yellow, White, Red, Orange, Blue, Gray and Black. They visit in different days starting from Monday to Sunday. 1) K visits one day after Thursday. 2) Only 4 people are in between K and L 3) The one who likes Red colour visits immediately after L. 4) Only one person visit between Red and Blue 5) The one who like white colour visit before one of days on which day M visits 6) The one who like white colour does not visit on Monday. 7) Only 1 person is in between N and O. N like Yellow. 8) There are same as many person in between K and Blue colour which are one less in between L and M. 9) Neither Q nor P likes Black. 10) Q does not visit on Saturday and does not like grey colour. Question : Who visits on Sunday and Tuesday and their favourite colors ? 2812 15b5cc6c2e4d2b4197774dba0
5b5cc6c2e4d2b4197774dba0- 1P & Mfalse
- 2N & Kfalse
- 3K & Ltrue
- 4P & Qfalse
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Answer : 3. "K & L"
Explanation :
Answer: C) K & L Explanation: Monday - N - Yellow Tuesday - L - White Wednesday - O - Red Thursday - Q - Orange Friday - M - Blue Saturday - P - Grey Sunday - K - Black From the above table, K & L visits Sunday & Tuesday and their favourite colors are Black and white respectively.
Q: Malleability and Ductility of metals can be accounted due to 2809 05b5cc670e4d2b4197774c052
5b5cc670e4d2b4197774c052- 1the crystalline structure in metalfalse
- 2the interaction of electrons with metal ions in the latticefalse
- 3the presence of electrostatic forcefalse
- 4the capacity of layers of metal ions to slide over the othertrue
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Answer : 4. "the capacity of layers of metal ions to slide over the other"
Explanation :
Answer: D) the capacity of layers of metal ions to slide over the other Explanation:
Q: The last two digits of 2151415? 2808 05b5cc6b9e4d2b4197774d6cb
5b5cc6b9e4d2b4197774d6cb- 181false
- 261false
- 391false
- 451true
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Answer : 4. "51"
Explanation :
Answer: D) 51 Explanation: Unit digit of this expression is always 1 as the base ends with 1. For the tenth place digit we need to multiply the digit in the tenth place of the base and unit digit of the power and take its unit digit. i.e, tenth place digit in 2151 is 5 and tenth place digit in power 415 is 1 And the units digit in the product of 5 x 1 = 5 Therefore, last two digits of 2151415 is 51.
Q: What is the term used in tennis when the score is 40-40? 2807 05b5cc67be4d2b4197774c20e
5b5cc67be4d2b4197774c20e- 1Acefalse
- 2Ledfalse
- 3Deucetrue
- 4Tiefalse
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Answer : 3. "Deuce"
Explanation :
Answer: C) Deuce Explanation: When both sides have won the same number of points then: when each side has won one, or two, points, the score is described as "15-all" and "30-all" (or "15-up" and "30-up"), respectively. However, if each player has won three points, the score is called as "deuce", not "40–all". From that point on in the game, whenever the score is tied, it is described as "deuce", regardless of how many points have been played.
Q: Which number replaces the '?' in the given series 108, 127, 2413, 2430, 41310, ?, 619875 2806 05b5cc767e4d2b4197774fdf2
5b5cc767e4d2b4197774fdf2- 141975false
- 241325true
- 384375false
- 441365false
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Answer : 2. "41325"
Explanation :
Answer: B) 41325 Explanation: The given series follows a pattern of +19, x19, +17, x17, +15, x15,... Here the number which is to be replaced in ? is 41310+15=41325.
Q: Planet : Orbit :: Projectile : ? 2801 05b5cc66de4d2b4197774bf9b
5b5cc66de4d2b4197774bf9b- 1Pathfalse
- 2Milky wayfalse
- 3Trackfalse
- 4Trajectorytrue
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Answer : 4. "Trajectory"
Explanation :
Answer: D) Trajectory Explanation: The path traced by planet is called Orbit. Similarly, the path traced by projectile is called Trajectory. Hence, Planet : Orbit : : Projectile : Trajectory.
Q: Find the Odd One Out? 4, 6, 12, 30, 81, 315. 2801 05b5cc6aae4d2b4197774cf56
5b5cc6aae4d2b4197774cf56- 16false
- 212false
- 381true
- 4315false
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Answer : 3. "81"
Explanation :
Answer: C) 81 Explanation: Given the number series is 4, 6, 12, 30, 81, 315. Here it follows a pattern that 4 4 x 1.5 = 6 6 x 2 = 12 12 x 2.5 = 30 30 x 3 = 90 not equals to 81 90 x 3.5 = 315 Hence the odd one in the series is 81.

