IIT JEE Practice Question and Answer
8Q: How many six digit odd numbers can be formed from the digits 0, 2, 3, 5, 6, 7, 8, and 9 (repetition not allowed)? 1617 05b5cc6b7e4d2b4197774d5f2
5b5cc6b7e4d2b4197774d5f2- 18640true
- 2720false
- 33620false
- 44512false
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Answer : 1. "8640"
Explanation :
Answer: A) 8640 Explanation: Let the 6 digits of the required 6 digit number be abcdef Then, the number to be odd number the last digit must be odd digit i.e 3, 5, 7 or 9 The first digit cannot be ‘0’ => possible digits = 3, 5, 7, 2, 6, 8 Remaining 4 places can be of 6 x 5 x 4 x 3 ways This can be easily understood by Therefore, required number of ways = 6 x 6 x 5 x 4 x 3 x 4 = 36 x 20 x 12 = 720 x 12 = 8640 ways.
Q: Which of the following is the strongest acid? 1352 05b5cc6b7e4d2b4197774d5ec
5b5cc6b7e4d2b4197774d5ec- 1ClCH2COOHfalse
- 2BrCH2COOHfalse
- 3FCH2COOHtrue
- 4ICH2COOHfalse
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Answer : 3. "FCH2COOH"
Explanation :
Answer: C) FCH2COOH Explanation: FCH2COOH is the strongest acid out of all .Since the electron withdrawing inductive effect (-I effect) of the halogens decreases in the order F>Cl> Br> I , therefore the acidic strength of the α- halo acids decreases in the same order. FCH2COOH > ClCH2COOH > BrCH2COOH > ICH2COOH.
Q: The sum of three consecutive odd numbers is 93. What is the middle number? 2152 05b5cc6b7e4d2b4197774d5e7
5b5cc6b7e4d2b4197774d5e7- 131true
- 233false
- 329false
- 427false
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Answer : 1. "31"
Explanation :
Answer: A) 31 Explanation: Let the three consecutive odd numbers be x, x+2, x+4 Then, x + x + 2 + x + 4 = 93 => 3x + 6 = 93 => 3x = 87 => x = 29 => 29, 31, 33 are three consecutive odd numbers. Therefore, the middle number is 31.
Q: In a college, number of boys is 75% of number of girls. Difference between boys and girls is 35. On a particular day 20% boys were absent, then find the number of boys those who present? 1534 05b5cc6b7e4d2b4197774d5e2
5b5cc6b7e4d2b4197774d5e2- 172false
- 284true
- 393false
- 481false
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Answer : 2. "84"
Explanation :
Answer: B) 84 Explanation: Ratio of girls and boys = 100% : 75% = 4:3 Difference is 1 unit = 35 So, 3 units = 35 x 3 = 105 If 20% absent, that’s mean 80% present. So, present boys = 80% of 105 = 80×105100 = 84
Q: A train travelling with a speed of 60 km/hr catches another train travelling in the same direction and then leaves it 120m behind in 18 seconds. The speed of the second train is 1634 05b5cc6b7e4d2b4197774d5dd
5b5cc6b7e4d2b4197774d5dd- 142 kmphfalse
- 272 kmphfalse
- 336 kmphtrue
- 444 kmphfalse
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Answer : 3. "36 kmph"
Explanation :
Answer: C) 36 kmph Explanation: Given speed of the first train = 60 km/hr = 60 x 5/18 = 50/3 m/s Let the speed of the second train = x m/s Then, the difference in the speed is given by 503 - x = 12018 => x = 10 m/s => 10 x 18/5 = 36 km/hr
Q: Hari Ram’s present age is three times his son’s present age and two fifth of his father’s present age. The average of the present age of all of them is 46 years. What is the difference between Hari Ram’s son’s present age and Hari Ram’s father’s present age? 5478 05b5cc6b7e4d2b4197774d5d8
5b5cc6b7e4d2b4197774d5d8- 144 yrsfalse
- 256 yrsfalse
- 367 yrsfalse
- 478 yrstrue
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Answer : 4. "78 yrs"
Explanation :
Answer: D) 78 yrs Explanation: Let Hari Ram's present age = x Then, his son's age = x/3 Father's age = 5x/2 x + x3 + 52x3 = 46=> x = 36 yrs Now the required difference = 52x36 - 363 = 78 yrs
Q: Largest Mint in India is at 1714 05b5cc6b7e4d2b4197774d5d3
5b5cc6b7e4d2b4197774d5d3- 1Mumbaifalse
- 2Hyderabadfalse
- 3Noidafalse
- 4Kolkatatrue
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Answer : 4. "Kolkata"
Explanation :
Answer: D) Kolkata Explanation: The Largest Mint in India is Kolkata Mint. Government of India operates 4 Mints in the country for the production of Coins. They are at Hyderabad, Telangana Mumbai, Maharashtra Kolkata, West Bengal Noida, Uttar Pradesh.
Q: 111 13 112 24 113 35 117 ? 2111 05b5cc6b7e4d2b4197774d5ce
5b5cc6b7e4d2b4197774d5ce- 146false
- 257false
- 368false
- 479true
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Answer : 4. "79"
Explanation :
Answer: D) 79
Explanation: The given puzzle follows a pattern that,
Number -

