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- Question
- If 2n + 1P n - 1 : 2n - 1P n = 3 : 5, then n is equal to?
Options- A. 4
- B. 6
- C. 3
- D. 8
- Correct Answer
- 4
ExplanationWe have If 2n + 1Pn - 1 / 2n - 1Pn = 3/5
? 5 x 2n + 1Pn - 1 = 3 x 2n - 1Pn
? {5 x (2n + 1)!} / {(n + 2 )!} = 3 x {(2n - 1)!} / {(n - 1)!}
? 10(2n + 1) = 3(n + 2) (n + 1)
? 3n2 - 11n - 4 = 0
?(3n + 1 ) (n - 4) = 0
? n = 4 - 1. In, ?ABC, D and E are the mid-points of AB and AC respectively. Find the ratio of the areas of ?ADE and ?ABC.
Options- A. 1 2
- B. 1 4
- C. 3 4
- D. 1 8 Discuss
- 2. 22020 ÷ 0.011=?
Options- A. 20020
- B. 2000000
- C. 200200
- D. 200002 Discuss
- 3. How many times are the hands of a clock is at right angle in a day?
Options- A. 22
- B. 24
- C. 44
- D. 48 Discuss
- 4. The unit digit in the product (784 x 618 x 917 x 463) is:
Options- A. 2
- B. 3
- C. 4
- D. 5 Discuss
- 5. If the true discount on s sum due 2 years hence at 14% per annum be Rs. 168, the sum due is:
Options- A. Rs. 768
- B. Rs. 968
- C. Rs. 1960
- D. Rs. 2400 Discuss
- 6. ?. 8x 2 + 6x = 5
?. 12y 2 ? 22y + 8 = 0
Options- A. 1
- B. 2
- C. 3
- D. 4 Discuss
- 7. 15, 31, 63, 127, 255, (...)?
Options- A. 513
- B. 511
- C. 517
- D. 523 Discuss
- 8. Find the probability that a vowel selected at random from the 5 vowels is an 'i'.?
Options- A. 4/5
- B. 1/3
- C. 1/5
- D. 1/2 Discuss
- 9. 396, 462, 572, 427, 671, 264
Options- A. 396
- B. 427
- C. 671
- D. 264 Discuss
- 10. If 90% of A = 30% of B and B = C% of A,then the value of C is?
Options- A. 900
- B. 800
- C. 600
- D. 300 Discuss
More questions
Correct Answer: 1 4
Explanation:
Correct Answer: 2000000
Explanation:
22020 ÷ 0.011 = 2001818.181 ? 2000000
Correct Answer: 44
Explanation:
In 12 h, they are at a right angles, 22 times.
So, in 24 h, they are at right angles, 44 times.
Correct Answer: 2
Explanation:
Unit digit in the given product = Unit digit in (4 x 8 x 7 x 3) = (672) = 2
Correct Answer: Rs. 768
Explanation:
| P.W. = | 100 x T.D. | = | 100 x 168 | = 600. |
| R x T | 14 x 2 |
∴ Sum = (P.W. + T.D.) = Rs. (600 + 168) = Rs. 768.
Correct Answer: 3
Explanation:
Correct Answer: 511
Explanation:
Each number is double the preceding one plus 1. So, the next number is (255 x 2) + 1 = 511.
Correct Answer: 1/5
Explanation:
Here, n(5) = {a, e, i,o, u}
and E = Event of selecting the vowel i = {i}
? P(E)= n(E)/n(S) = 1/5
Correct Answer: 427
Explanation:
In each number except 427, the middle digit is the sum of other two.
Correct Answer: 300
Explanation:
? 90A/100 = 30B/100 = (30/100) x AC/100
? C = 100 x (100/30) x (90/100) = 300
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