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- Question
- An intelligence agency forms a code of two distinct digits selected from 0, 1, 2,....., 9 such that the first-digit of code is non-zero. The code, handwritten on a slip, can however potentially create confusion when read upside down, for examples the code 91 may appear as 16. how many codes are there for which no such confusion can arise?
Options- A. 80
- B. 78
- C. 71
- D. 69
- Correct Answer
- 69
ExplanationThe available digits are 0, 1, 2,...., 9. The first digit can be chosen in 9 ways (0 not acceptable), the second digit can be accepted in 9 ways (digit repetition not allowed). Thus, the code can be made in 9 x 9 = 81 ways.
Now, there are only 4 digits which can create confusion 1, 6, 8, 9. The same can be given in the following ways
Total number of ways confusion can arise
= 4 x 3 = 12
Thus, the ways in which no such confusion arise = 81-12 =69 - 1. An elevator starts with 5 passengers and stops at 8 different floors if the house. Find out the probability of all the 5 passengers alighting at different floors.
Options- A. 101/512
- B. 105/512
- C. 107/512
- D. 109/512 Discuss
- 2. A single discount equivalent to three successive discounts of 5% , 10% , 20% is :
Options- A. 68.4 %
- B. 35 %
- C. 31.6 %
- D. 32 % Discuss
- 3. The discount on $ 5229 due in 1 year 9 months reckoning compound interest at 5 % is :
Options- A. $ 429.00
- B. $ 415.00
- C. $ 393.25
- D. None of these Discuss
- 4. If $ 10 be allowed as true discount on a bill of $ 110 due at the end of certain time, then the discount allowed on the same amount due at the end of double the time is :
Options- A. $ 20
- B. $ 21.81
- C. $ 22
- D. $ 18.33 Discuss
- 5. ?. 10x 2 ? 7x + 1 = 0
?. 35y 2 -12y + 1 = 0
Options- A. 1
- B. 2
- C. 3
- D. 4 Discuss
- 6. Abhinav save Rs. 25 by getting 6.66% discount on a textbook.What is the amount of money (in Rs.) paid by him?
Options- A. 450
- B. 350
- C. 225
- D. 375 Discuss
- 7. ?. x 3 - 371 = 629
?. y 3 - 543 = 788
Options- A. 1
- B. 2
- C. 3
- D. 4 Discuss
- 8. The roots of the equation a2x2 - 3abx + 2b2 = 0 are
Options- A. 2b , - b a a
- B. 2b , b a a
- C. - 2b , - b a a
- D. None of these Discuss
- 9. 1, 8, 27, 64, 125, 216, (...) :
Options- A. 354
- B. 343
- C. 392
- D. 245 Discuss
- 10. The Different between the length and breadth of a rectangle is 23 m. If its perimeter is 206 m, then its area is
Options- A. 2520 m2
- B. 2480 m2
- C. 2420 m2
- D. None of these Discuss
More questions
Correct Answer: 105/512
Explanation:
Required probability = favorable number of cases/ total number of
=8P5 / 8 5 = 105/512
Correct Answer: 31.6 %
Explanation:
Let the original price be 100 Rs.
So reduced price = 100 X 0.95 X 0.90 X 0.80 = 68.40
? Single discount = (100 ? 68.4) % = 31.6%
Correct Answer: $ 429.00
Explanation:
Correct Answer: $ 18.33
Explanation:
Correct Answer: 4
Explanation:
Correct Answer: 350
Explanation:
6.66% of MP = 25
? MP = 375
? SP = MP - 25 = 350
Correct Answer: 3
Explanation:
According to given question , we have
?. x3 - 371 = 629
? x = ?1000 = 10
?. y3 - 543 = 788
? y = ?1331 = 11
From above both equations it is clear that x < y is correct answer .
Correct Answer: 2b , b a a
Explanation:
Correct Answer: 343
Explanation:
Number are 13, 23, 33, 43, 53, 63.
So, the missing number is 73 = 343.
Correct Answer: 2520 m2
Explanation:
Let the length of rectangle = L m
? Breadth of rectangle = B m
Using conditions from the question,
L - B = 23 ....(i)
2(L + B) = 206
L + B = 103 ....(ii)
On adding Eqs. (i) and (ii), we get
2L = 126
? L = 63 m
? B = 103 - 63 = 40 m
Then , area of rectangle = L x B
= 63 x 40
= 2520 m2 .
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