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प्र: Ajay and his wife Reshmi appear in an interview for two vaccancies in the same post. The Probability of Ajay's selection is 1/7 and that of his wife Reshmi's selection is 1/5. What is the probability that only one of them will be selected? 1632 0

उत्तर : 3. "2/7"
व्याख्या :
Answer: C) 2/7 Explanation: P( only one of them will be selected) = p[(E and not F) or (F and not E)] = PE∩F∪F∩E = PEPF+PFPE =17×45+15×67=27

प्र: A passenger train is moving at a speed of 120 km/hr. If the length of the train is 101 meters, how long will it take to cross a railway platform 154 meters long ? 1631 0

उत्तर : 4. "7.65 sec"
व्याख्या :
Answer: D) 7.65 sec Explanation: Here total distance = 154 + 101 = 255 mtsGiven speed = 120 kmph = 120x5/18 m/secHence, Time = d/s = 255x18/120x5 = 7.65 sec

प्र: The cost price of an article is 54% of the marked price. Calculate the gain percent after allowing a discount of 15% ? 1630 0

उत्तर : 3. "48.4 %"
व्याख्या :
Answer: C) 48.4 % Explanation: Let marked price = Rs. 100. Then, C.P. = RS. 54, S.P. = Rs. 85Gain % = 31/64 x 100 = 48.4%.

प्र: The probability that a number selected at random from the first 100 natural numbers is a composite number is ? 1629 0

उत्तर : 1. "3/2"
व्याख्या :
Answer: A) 3/2 Explanation: The number of exhaustive events = 100 C₁ = 100. We have 25 primes from 1 to 100. Number of favourable cases are 75. Required probability = 75/50 = 3/2.

प्र: If 1/a+1/b+1/c = 1/(a+b+c) where a+b+c not equals '0', abc not equals '0', What is the value of (a+b) (b+c) (a+c) ? 1628 0

उत्तर : 4. "0"
व्याख्या :
Answer: D) 0 Explanation: Let assume the value of a,b &c that will satisfy the equation.so a=1,b=1,c= -1 or a=1,b= -1 &c=1 or a= -1,b=1,c=1here all three cases satisfy the equationassume any one a=1,b=1,c= -1 Hence (a+b)(b+c)(c+a)=(1+1)(1-1)(-1+1) = 0

प्र: From a group of 7 boys and 6 girls, five persons are to be selected to form a team, so that at least 3 girls are there in the team. In how many ways can it be done? 1628 0

उत्तर : 2. "531"
व्याख्या :
Answer: B) 531 Explanation: Given in the question that, there are 7 boys and 6 girls. Team members = 5 Now, required number of ways in which a team of 5 having atleast 3 girls in the team = 6C3 x 7C2 + 6C4 x 7C1 + 6C5= 6x5x43x2x1 x 7x62x1 + 6x5x4x34x3x2x1 x 7 + 6x5x4x3x25x4x3x2x1= 420 + 105 + 6= 531.

प्र: The length, breadth and height of a room are in the ratio 7:3:1. If the breadth and height are doubled while the length is halved, then by what percent the total area of the 4 walls of the room will be increased ? 1627 0

उत्तर : 1. "90%"
व्याख्या :
Answer: A) 90% Explanation: Let length, breadth and height of the room be 7, 3, 1 unit respectively. Area of walls = 2(l+b)xh = 2(7+3)x1 = 20 sq. unit. Now, length, breadth and height of room will become 3.5, 6 and 2 respectively. Area of walls = 2(l+b)xh = 2(3.5+6)x2 = 38 sq. unit. % Increase in the area of walls = (38-20)x100/20 = 90%.

प्र: How many iron rods, each of length 7 mts and diameter 2 cms can be made out of 0.88 cubic metre of iron ? 1627 0

उत्तर : 3. "400"
व्याख्या :
Answer: C) 400 Explanation: Given length of iron rod =7 mts and and diameter of rod = 2 cms => r = 1/100 mts Therefore, Volume of one rod = πr2h cu. m = 227×11002×7cu. m = 115000 cu. m Given volume of iron = 0.88 cu. m Therefore, Number of rods = 0.88×500011 = 400.

प्र: Ajay and his wife Reshmi appear in an interview for two vaccancies in the same post. The Probability of Ajay's selection is 1/7 and that of his wife Reshmi's selection is 1/5. What is the probability that only one of them will be selected? 1632 0

उत्तर : 3. "2/7"
व्याख्या :
Answer: C) 2/7 Explanation: P( only one of them will be selected) = p[(E and not F) or (F and not E)] = PE∩F∪F∩E = PEPF+PFPE =17×45+15×67=27

प्र: A passenger train is moving at a speed of 120 km/hr. If the length of the train is 101 meters, how long will it take to cross a railway platform 154 meters long ? 1631 0

उत्तर : 4. "7.65 sec"
व्याख्या :
Answer: D) 7.65 sec Explanation: Here total distance = 154 + 101 = 255 mtsGiven speed = 120 kmph = 120x5/18 m/secHence, Time = d/s = 255x18/120x5 = 7.65 sec

प्र: The cost price of an article is 54% of the marked price. Calculate the gain percent after allowing a discount of 15% ? 1630 0

उत्तर : 3. "48.4 %"
व्याख्या :
Answer: C) 48.4 % Explanation: Let marked price = Rs. 100. Then, C.P. = RS. 54, S.P. = Rs. 85Gain % = 31/64 x 100 = 48.4%.

प्र: The probability that a number selected at random from the first 100 natural numbers is a composite number is ? 1629 0

उत्तर : 1. "3/2"
व्याख्या :
Answer: A) 3/2 Explanation: The number of exhaustive events = 100 C₁ = 100. We have 25 primes from 1 to 100. Number of favourable cases are 75. Required probability = 75/50 = 3/2.

प्र: If 1/a+1/b+1/c = 1/(a+b+c) where a+b+c not equals '0', abc not equals '0', What is the value of (a+b) (b+c) (a+c) ? 1628 0

प्र: From a group of 7 boys and 6 girls, five persons are to be selected to form a team, so that at least 3 girls are there in the team. In how many ways can it be done? 1628 0

प्र: The length, breadth and height of a room are in the ratio 7:3:1. If the breadth and height are doubled while the length is halved, then by what percent the total area of the 4 walls of the room will be increased ? 1627 0

प्र: How many iron rods, each of length 7 mts and diameter 2 cms can be made out of 0.88 cubic metre of iron ? 1627 0

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प्र: Ajay and his wife Reshmi appear in an interview for two vaccancies in the same post. The Probability of Ajay's selection is 1/7 and that of his wife Reshmi's selection is 1/5. What is the probability that only one of them will be selected? 1632 05b5cc7d0e4d2b41977751222

उत्तर : 3. "2/7" व्याख्या :Answer: C) 2/7 Explanation: P( only one of them will be selected) = p[(E and not F) or (F and not E)] = PE∩F∪F∩E = PEPF+PFPE =17×45+15×67=27

प्र: A passenger train is moving at a speed of 120 km/hr. If the length of the train is 101 meters, how long will it take to cross a railway platform 154 meters long ? 1631 05b5cc6d3e4d2b4197774e540

उत्तर : 4. "7.65 sec" व्याख्या :Answer: D) 7.65 sec Explanation: Here total distance = 154 + 101 = 255 mtsGiven speed = 120 kmph = 120x5/18 m/secHence, Time = d/s = 255x18/120x5 = 7.65 sec

प्र: The cost price of an article is 54% of the marked price. Calculate the gain percent after allowing a discount of 15% ? 1630 05b5cc6d6e4d2b4197774e660

उत्तर : 3. "48.4 %" व्याख्या :Answer: C) 48.4 % Explanation: Let marked price = Rs. 100. Then, C.P. = RS. 54, S.P. = Rs. 85Gain % = 31/64 x 100 = 48.4%.

प्र: The probability that a number selected at random from the first 100 natural numbers is a composite number is ? 1629 05b5cc6e3e4d2b4197774ec8e

उत्तर : 1. "3/2" व्याख्या :Answer: A) 3/2 Explanation: The number of exhaustive events = 100 C₁ = 100. We have 25 primes from 1 to 100. Number of favourable cases are 75. Required probability = 75/50 = 3/2.

प्र: If 1/a+1/b+1/c = 1/(a+b+c) where a+b+c not equals '0', abc not equals '0', What is the value of (a+b) (b+c) (a+c) ? 1628 05b5cc709e4d2b4197774f258

प्र: From a group of 7 boys and 6 girls, five persons are to be selected to form a team, so that at least 3 girls are there in the team. In how many ways can it be done? 1628 05b5cc675e4d2b4197774c115

प्र: The length, breadth and height of a room are in the ratio 7:3:1. If the breadth and height are doubled while the length is halved, then by what percent the total area of the 4 walls of the room will be increased ? 1627 05b5cc6c6e4d2b4197774de18

प्र: How many iron rods, each of length 7 mts and diameter 2 cms can be made out of 0.88 cubic metre of iron ? 1627 05b5cc77fe4d2b419777501c4

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प्र: Ajay and his wife Reshmi appear in an interview for two vaccancies in the same post. The Probability of Ajay's selection is 1/7 and that of his wife Reshmi's selection is 1/5. What is the probability that only one of them will be selected? 1632 0

उत्तर : 3. "2/7"
व्याख्या :
Answer: C) 2/7 Explanation: P( only one of them will be selected) = p[(E and not F) or (F and not E)] = PE∩F∪F∩E = PEPF+PFPE =17×45+15×67=27

प्र: A passenger train is moving at a speed of 120 km/hr. If the length of the train is 101 meters, how long will it take to cross a railway platform 154 meters long ? 1631 0

उत्तर : 4. "7.65 sec"
व्याख्या :
Answer: D) 7.65 sec Explanation: Here total distance = 154 + 101 = 255 mtsGiven speed = 120 kmph = 120x5/18 m/secHence, Time = d/s = 255x18/120x5 = 7.65 sec

प्र: The cost price of an article is 54% of the marked price. Calculate the gain percent after allowing a discount of 15% ? 1630 0

उत्तर : 3. "48.4 %"
व्याख्या :
Answer: C) 48.4 % Explanation: Let marked price = Rs. 100. Then, C.P. = RS. 54, S.P. = Rs. 85Gain % = 31/64 x 100 = 48.4%.

प्र: The probability that a number selected at random from the first 100 natural numbers is a composite number is ? 1629 0

उत्तर : 1. "3/2"
व्याख्या :
Answer: A) 3/2 Explanation: The number of exhaustive events = 100 C₁ = 100. We have 25 primes from 1 to 100. Number of favourable cases are 75. Required probability = 75/50 = 3/2.

प्र: If 1/a+1/b+1/c = 1/(a+b+c) where a+b+c not equals '0', abc not equals '0', What is the value of (a+b) (b+c) (a+c) ? 1628 0

प्र: From a group of 7 boys and 6 girls, five persons are to be selected to form a team, so that at least 3 girls are there in the team. In how many ways can it be done? 1628 0

प्र: The length, breadth and height of a room are in the ratio 7:3:1. If the breadth and height are doubled while the length is halved, then by what percent the total area of the 4 walls of the room will be increased ? 1627 0

प्र: How many iron rods, each of length 7 mts and diameter 2 cms can be made out of 0.88 cubic metre of iron ? 1627 0