IIT JEE Practice Question and Answer
8Q: In a box, there are 9 blue, 6 white and some black stones. A stone is randomly selected and the probability that the stone is black is ┬╝. Find the total number of stones in the box? 1675 05b5cc64ae4d2b4197774bc47
5b5cc64ae4d2b4197774bc47- 115false
- 218false
- 320true
- 424false
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Answer : 3. "20"
Explanation :
Answer: C) 20 Explanation: We know that, Total probability = 1 Given probability of black stones = 1/4 => Probability of blue and white stones = 1 - 1/4 = 3/4 But, given blue + white stones =┬а 9 + 6 = 15 Hence, 3/4 ----- 15 ┬а1┬а ┬а-----┬а ? => 15 x 4/3 = 20. ┬а Hence, total number of stones in the box = 20.
Q: What is a Common Multiple? 1675 05b5cc6b5e4d2b4197774d548
5b5cc6b5e4d2b4197774d548- Show AnswerHide Answer
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Answer :
Explanation :
If the Multiples for two or more numbers which are┬аCommon, then those Multiples are said to be Common Multiples.┬а ┬а For Example : Multiples of 3 are 3, 6, 9, 12, 15, 18, 21, 24, 27, 30,... Multiples of 5 are 5, 10, 15, 20, 25, 30,... Here common multiples of 3 & 5 upto 30 are 15, 30.
Q: In a mixture of 240 lt. water is 20% and rest is Milk. What quantity of mixture should be taken out and replaced with water so that water becomes 40%? 1675 05b5cc6bee4d2b4197774d98d
5b5cc6bee4d2b4197774d98d- 160 littrue
- 255 litfalse
- 345 litfalse
- 450 litfalse
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Answer : 1. "60 lit"
Explanation :
Answer: A) 60 lit Explanation:
Q: How many seconds will a 600 m long train take to cross a man walking with a speed of 7 km/hr in the direction of the moving train if the speed of the train is 67 km/hr ? 1674 05b5cc6dfe4d2b4197774eb20
5b5cc6dfe4d2b4197774eb20- 129 secfalse
- 258 secfalse
- 336 sectrue
- 444 secfalse
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Answer : 3. "36 sec"
Explanation :
Answer: C) 36 sec Explanation: Speed of train relative to man = 67 - 7 = 60 km/hr.= 60 x 5/18 = 50/3 m/sec. Time taken to pass the man = 600 x 3/50 = 36 sec.
Q: OrkutтАЩs creator Buyukkokten has launched a new social network called ________, which is available on mobile only. 1674 05b5cc6dde4d2b4197774e9f6
5b5cc6dde4d2b4197774e9f6- 1Callerfalse
- 2Hellotrue
- 3Hifalse
- 4Hayfalse
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Answer : 2. "Hello"
Explanation :
Answer: B) Hello Explanation: OrkutтАЩs creator Buyukkokten has launched a new social network called Hello, which is available on mobile only. The Hello.com app is available on Android and iOS in the following countries: US, Canada, Britain, France, Australia, Brazil, Ireland. Germany, Mexico and India are next on the list and the app should be available this month.
Q: What will come in the place of the (?) in the following number series ? 5 14 45 130 (?) 1182 1673 05b5cc6cae4d2b4197774e095
5b5cc6cae4d2b4197774e095- 1222false
- 2397true
- 3404false
- 4415false
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Answer : 2. "397"
Explanation :
Answer: B) 397 Explanation: The pattern of given series is : 5 14 = (5x3) - 1 45 = (14x3) + 3 130 = (45x3) - 5 (?) = (130x3) + 7 => (?) = 397 1182 = (397x3) - 9 Thus, the missing number is 397.
Q: Which of the following elements is a metalloid? 1673 05b5cc622e4d2b4197774b7ce
5b5cc622e4d2b4197774b7ce- 1arsenicfalse
- 2boronfalse
- 3antimonyfalse
- 4All of the abovetrue
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Answer : 4. "All of the above"
Explanation :
Answer: D) All of the above Explanation: A metalloid is any chemical element which has properties in between those of metals and nonmetals, or that has a mixture of them. The six commonly recognised metalloids are boron, silicon, germanium, arsenic, antimony, and tellurium.
Q: What has 3 feet but cannot walk? 1673 05b5cc672e4d2b4197774c0cd
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Answer :
Explanation :
We know that 1 yard = 3 feet.┬а ┬а A yardstick which is used for measurement has 3 feet long but it cannot walk.