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- Question
The difference between a two-digit number and the number obtained by interchanging the positions of its digits is 36. What is the difference between the two digits of that number?
Options- A. 3
- B. 4
- C. 9
- D. Cannot be determined
- E. None of these
- Correct Answer
- 4
ExplanationLet the ten's digit be x and unit's digit be y.Then, (10x + y) - (10y + x) = 36
⟹ 9(x - y) = 36
⟹ x - y = 4.
More questions
- 1. Write down the power set of A = {8, 9}.
Options- A. {?, {8}, {9}, {8, 9}}
- B. {?, {8}, {9}}
- C. {?, {8}, {9}, {8, 9}}
- D. None of these Discuss
Correct Answer: {?, {8}, {9}, {8, 9}}
Explanation:
NA
- 2. The area of two similar ?s are 121 cm 2 and 81 cm 2 respectively. What is the ratio of their corresponding heights (altitudes):
Options- A. 11 9
- B. 22 9
- C. 11 18
- D. 33 6 Discuss
Correct Answer: 11 9
Explanation:
- 3. In how many different ways, can the letters of the word 'VENTURE' be arranged?
Options- A. 840
- B. 5040
- C. 1260
- D. 2520 Discuss
Correct Answer: 2520
Explanation:
The required different ways = 7 ! / 2 !
= 7 x 6 x 5 x 4 x 3 x 2!/2!
= 2520- 4. Alen and Border can do a work individually in 21 and 42 days respectively. In how many days they can complete the work, working alternatively?
Options- A. 14
- B. 28
- C. 42
- D. 35 Discuss
Correct Answer: 28
Explanation:
Alen's one day's work =1/21
Border's one day's work = 1/42
Alen and Border's two days work(working alternatively) = (1/21) + (1/42) = 1/14
So, Alen and Border do 1/14 work in 2 days
So, they complete the work in 14 x 2 = 28 days.- 5. A number is selected at random from the set {1, 2, 3, ........, 50}. The probability that it is a prime, is
Options- A. 0.1
- B. 0.2
- C. 0.3
- D. 0.3 Discuss
Correct Answer: 0.3
Explanation:
n(s) = 50
Prime numbers are = 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47
? n(E) = 15
? p(E) = 15/50 = 3/10 = 0.3- 6. Sonu can do a piece of work in 20 days. He started the work and left after some days, when 25% work was done. After it Abhijeet joined and completed it working for 10 days. In how many days Sonu and Abhijeet can do the complete work, working together?
Options- A. 6
- B. 8
- C. 10
- D. 12 Discuss
Correct Answer: 8
Explanation:
Efficiency of Sonu = (100/20) = 5%
Rest work = 75%
? Efficiency of Abhijeet = 75/10 = 7.5%
? Combined efficiency of Sonu and Abhijeet = 7.5 + 5 = 12.5%
? Number of days required by Sonu and Abhijeet, to work togethere = 100/12.5 = 8days- 7. 19.003 x 22.998 - 280.010
Options- A. 220
- B. 110
- C. 160
- D. 90 Discuss
Correct Answer: 160
Explanation:
? = 19.003 x 22.998 - 280.010
? 19 x 23 - 280 ? 437 -280
? 157 ? 160- 8. A person buys a book for ? 200 and sells it for ? 225. What will be his gain percent?
Options- A. 13%
- B. 14%
- C. 18.4%
- D. 12.5% Discuss
Correct Answer: 12.5%
Explanation:
Given that, CP = ? 200 and SP = ? 225
Profit = SP - CP = 225 - 200 = ? 25
? Gain% = [profit/CP] x 100%
= (25/200) x 100% = 12.5%- 9. 3, 7, 15, 39, 63, 127, 255, 511?
Options- A. 7
- B. 15
- C. 39
- D. 63 Discuss
Correct Answer: 39
Explanation:
Go on multiplying 2 and adding 1 to get the next number. So, 39 is wrong.
- 10. If A = { x : x = n-1/n+1, n ? W and n ? 10 } ;point out the correct statement from the following:
Options- A. 0 ? A
- B. 0 ? A
- C. 0 ? A
- D. 1/3 ? A Discuss
Correct Answer: 0 ? A
Explanation:
NA
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