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- Question
What is the unit digit in(795 - 358)?
Options- A. 0
- B. 4
- C. 6
- D. 7
- Correct Answer
- 4
Explanation
Unit digit in 7 95 = Unit digit in [(7 4 ) 23 x 7 3 ]
= Unit digit in [(Unit digit in(2401)) 23 x (343)]
= Unit digit in (1 23 x 343)
= Unit digit in (343)
= 3Unit digit in 358 = Unit digit in [(34)14 x 32]
= Unit digit in [Unit digit in (81)14 x 32]
= Unit digit in [(1)14 x 32]
= Unit digit in (1 x 9)
= Unit digit in (9)
= 9Unit digit in (795 - 358) = Unit digit in (343 - 9) = Unit digit in (334) = 4.
So, Option B is the answer.
- 1. (51+ 52 + 53 + ... + 100) =?
Options- A. 2525
- B. 2975
- C. 3225
- D. 3775 Discuss
- 2. 587 x 999 =?
Options- A. 586413
- B. 587523
- C. 614823
- D. 615173 Discuss
- 3. (112 x 54) =?
Options- A. 67000
- B. 70000
- C. 76500
- D. 77200 Discuss
- 4. 106 x 106 - 94 x 94 =?
Options- A. 2400
- B. 2000
- C. 1904
- D. 1906
- E. None of these Discuss
- 5. (1000)9? 1024 =?
Options- A. 10000
- B. 1000
- C. 100
- D. 10
- E. None of these Discuss
- 6. The smallest 5 digit number exactly divisible by 41 is:
Options- A. 1004
- B. 10004
- C. 10045
- D. 10025
- E. None of these Discuss
- 7. 4500 x? = 3375
Options- A. 2⁄5
- B. 3⁄4
- C. 1⁄4
- D. 3⁄5
- E. None of these Discuss
- 8. What value should come in place of the question mark(?) in the following question? (?) + 3699 + 1985 - 2047 = 31111
Options- A. 34748
- B. 27474
- C. 30154
- D. 27574
- E. None of these Discuss
- 9. 72519 x 9999 =?
Options- A. 725117481
- B. 674217481
- C. 685126481
- D. 696217481
- E. None of these Discuss
- 10. The difference of the squares of two consecutive odd integers is divisible by which of the following integers?
Options- A. 3
- B. 6
- C. 7
- D. 8 Discuss
Numbers problems
Search Results
Correct Answer: 3775
Explanation:
This is an A.P. in which a = 51, l = 100 and n = 50.
| ∴Sum = | n | (a + l) | = | 50 | x (51 + 100) = (25 x 151) = 3775. |
| 2 | 2 |
Correct Answer: 586413
Explanation:
| 587 x 999 | = 587 x (1000 - 1) |
| = 587 x 1000 - 587 x 1 | |
| = 587000 - 587 | |
| = 586413. |
Correct Answer: 70000
Explanation:
| (112 x 54) = 112 x | ❨ | 10 | ❩ | 4 | = | 112 x 104 | = | 1120000 | = 70000 |
| 2 | 24 | 16 |
Correct Answer: 2400
Explanation:
| 106 x 106 - 94 x 94 | = (106)2 - (94)2 |
| = (106 + 94)(106 - 94) [Ref: (a2 - b2) = (a + b)(a - b) ] | |
| = (200 x 12) | |
| = 2400. |
Correct Answer: 1000
Explanation:
| Given Exp. = | (1000)9 | = | (103)9 | = | (10)27 | = 10(27-24) = 103 = 1000 |
| 1024 | 1024 | 1024 |
Correct Answer: 10004
Explanation:
The smallest 5-digit number = 10000.
41) 10000 (243
82
---
180
164
----
160
123
---
37
---
Required number = 10000 + (41 - 37)
= 10004.
Correct Answer: 3⁄4
Explanation:
| 4500 x x = 3375 ⟹ x = | = | 3 | |
| 4 |
Correct Answer: 27474
Explanation:
x + 3699 + 1985 - 2047 = 31111
⟹ x + 3699 + 1985 = 31111 + 2047
⟹ x + 5684 = 33158
⟹ x = 33158 - 5684 = 27474.
Correct Answer: 725117481
Explanation:
| 72519 x 9999 | = 72519 x (10000 - 1) |
| = 72519 x 10000 - 72519 x 1 | |
| = 725190000 - 72519 | |
| = 725117481. |
Correct Answer: 8
Explanation:
Let the two consecutive odd integers be (2 n + 1) and (2 n + 3). Then,
(2n + 3)2 - (2n + 1)2 = (2n + 3 + 2n + 1) (2n + 3 - 2n - 1)
= (4n + 4) x 2
= 8(n + 1), which is divisible by 8.
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