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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
How many 3-digit numbers can be formed by using the digits 1 to 9 if no digit is repeated? |
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Answer» No. of ways of filling first place = 9 No. of ways of filling second place = 8 No. of ways of fillin third place = 7 Therefore, total numbers `= 89 xx 8 xx 7 504`. |
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| 2. |
How many 6-digit numbers can be formed from the digits 0,3,5,7 and 9 which are divisible by 10 and no digits is repeated? |
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Answer» Since numbers are divisible by 10, so there will always be 0 at unit place. No. of ways of placing remaining 5 digits at 5 places `= .^(5)P_(5) = 5! = 120` Total numbers `= 120` |
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| 3. |
If `C(n,12) = C(n,16)`, then `C(30,n) = ?`A. 435B. 870C. 420D. None of these |
| Answer» Correct Answer - A | |
| 4. |
If `P(n,6) = 30. P)(n,4)` then `n = ?`A. 10B. 9C. 8D. None of these |
| Answer» Correct Answer - A | |
| 5. |
No. of positive integral solutions of the equation `abc = 42` is:A. 27B. 30C. 6D. None of these |
| Answer» Correct Answer - A | |
| 6. |
No. of combinations by selecting one or more than one object out of n objects is:A. `2^(n-1)`B. `2^(n-1)`C. `2^(n)`D. None of these |
| Answer» Correct Answer - B | |
| 7. |
`lfloor24` is divisible by:A. `6^(24)`B. `24^(6)`C. `48^(6)`D. None of these |
| Answer» Correct Answer - B | |
| 8. |
No of 4 digit numbers formed with the digits 3,4,5 and 6 which are divisible by 5, are:A. 24B. 12C. 6D. 3 |
| Answer» Correct Answer - C | |
| 9. |
The sum of all five digit numbers formed with the digits 1,2,3,4,5 without repetition of digits areA. 3,00,000B. 3,60,000C. 3,90,000D. None of these |
| Answer» Correct Answer - D | |
| 10. |
No. of even 6 digits numbers, without repetition of digits, using digits 1,2,3,4,5,6,7 are:A. 720B. 288C. 144D. None of these |
| Answer» Correct Answer - A | |
| 11. |
No. of selections of one or more balls from 10 white, 9 black and 4 red balls, are:A. 360B. 359C. 549D. None of these |
| Answer» Correct Answer - C | |