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- Question
If A1, A2, A3, A4, ..... A10 are speakers for a meeting and A1 always speaks after, A2 then the number of ways they can speak in the meeting is
Options- A. 9!
- B. 9!/2
- C. 10!
- D. 10!/2
- Correct Answer
- 10!/2
ExplanationAs A1 speaks always after A2, they can speak only in 1st to 9th places and
A2 can speak in 2nd to 10 the places only when A1 speaks in 1st place
A2 can speak in 9 places the remaining
A3, A4, A5,...A10 has no restriction. So, they can speak in 9.8! ways. i.e
when A2 speaks in the first place, the number of ways they can speak is 9.8!.
When A2 speaks in second place, the number of ways they can speak is 8.8!.
When A2 speaks in third place, the number of ways they can speak is 7.8!. When A2 speaks in the ninth place, the number of ways they can speak is 1.8!
Therefore,Total Number of ways they can speak = (9+8+7+6+5+4+3+2+1) 8! = = 10!/2
- 1. A train 300 meters long passes a standing man is 15 seconds. The speed of the train is?
Options- A. 40 km/hr
- B. 50 km/hr
- C. 60 km/hr
- D. 72 km/hr Discuss
- 2. If the diagonal of a square is double, how does the area of the square change?
Options- A. Becomes four fold
- B. Becomes three fold
- C. Becomes two fold
- D. None of the above Discuss
- 3. 46080, 3840, 384, 48, 24, 2, 1
Options- A. 1
- B. 2
- C. 24
- D. 384 Discuss
- 4. The difference between the length and breadth of a rectangle is 23 m. If its perimeter is 206 m, then its area is:
Options- A. 1520 m2
- B. 2420 m2
- C. 2480 m2
- D. 2520 m2 Discuss
- 5. 4/5 of a number exceeds its 2/3 by 8. The number is?
Options- A. 30
- B. 60
- C. 90
- D. None of these Discuss
- 6. Find the angle between minute hand and hour hand at 2 : 18 AM
Options- A. 37°
- B. 33°
- C. 39°
- D. None of these Discuss
- 7. Rakesh, Dinesh and Mahesh start a business by investing ? 5000 , ? 8000 and ? 12000 , respectively . At the end of year, they got the profit of ? 12500. What is the share of Dinesh in profit?
Options- A. ? 4000
- B. ? 4500
- C. ? 6000
- D. ? 7500 Discuss
- 8. The least multiple of 7, which leaves a remainder of 4, when divided by 6, 9, 15 and 18 is:
Options- A. 74
- B. 94
- C. 184
- D. 364 Discuss
- 9. If log 27 = 1.431, then the value of log 9 is:
Options- A. 0.934
- B. 0.945
- C. 0.954
- D. 0.958 Discuss
- 10. A box contains 2 white balls, 3 black balls and 4 red balls. In how many ways can 3 balls be drawn from the box, if at least one black ball is to be included in the draw?
Options- A. 32
- B. 48
- C. 64
- D. 96
- E. None of these Discuss
More questions
Correct Answer: 72 km/hr
Explanation:
? Speed = Distance / Time = (300/15)
= 20 m/sec
= (20 x 18) / 5 = 72 km/hr
Correct Answer: Becomes four fold
Explanation:
Ratio of the areas = area of original square / area of new square
= [ d2 / 2 ] / [ (2d)2 / 2 ] = 1/4
? New area becomes 4 fold.
Correct Answer: 24
Explanation:
So, 24 is wrong, it should be 8 (48/6 = 8).
Correct Answer: 2520 m2
Explanation:
Solving the two equations, we get: l = 63 and b = 40.
∴ Area = (l x b) = (63 x 40) m2 = 2520 m2.
Correct Answer: 60
Explanation:
Let the number be x,
Then, 4x/5 - 2x/3 = 8
? (12x - 10x) / 15 = 8
? 2x = 120
? x = 60
Correct Answer: 39°
Explanation:
39°
Correct Answer: ? 4000
Explanation:
Share of Rakesh : Share of Dinesh : Share of Mahesh
= 5000 : 8000 : 12000 = 5 : 8 : 12
Total earned profit = ? 12500
? Share of Dinesh in profit
= [8/(5 + 8 + 12)] x 12500 = (8/25) x 12500
= 8 x 500 = ? 4000
Correct Answer: 364
Explanation:
L.C.M. of 6, 9, 15 and 18 is 90.
Let required number be 90k + 4, which is multiple of 7.
Least value of k for which (90k + 4) is divisible by 7 is k = 4.
∴ Required number = (90 x 4) + 4 = 364.
Correct Answer: 0.954
Explanation:
⟹ log (33 ) = 1.431
⟹ 3 log 3 = 1.431
⟹ log 3 = 0.477
∴ log 9 = log(32 ) = 2 log 3 = (2 x 0.477) = 0.954.
Correct Answer: 64
Explanation:
| ∴ Required number of ways | = (3C1 x 6C2) + (3C2 x 6C1) + (3C3) | |||||||||||||
|
||||||||||||||
| = (45 + 18 + 1) | ||||||||||||||
| = 64. |
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