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- Question
- What is th unit digit in ( 3 65+6 59+7 71 )?
Options- A. 6
- B. 4
- C. 2
- D. 1
- Correct Answer
- 4
ExplanationUnit digit in 34 = 1
? Unit digit in ( 34 )16 = 1
? Unit digit in 365 = 3
Unit digit in 659 = 6
Unit digit in 771 = 3
? Required unit digit = Unit digit in ( 3 x 6 x 3 )
= Unit digit in 54
= 4 - 1. What is the unit digit in the ( 6817 ) 754?
Options- A. 8
- B. 4
- C. 2
- D. 9 Discuss
- 2. Sum of first 15 multiple of 8 is
Options- A. 960
- B. 660
- C. 1200
- D. 1060 Discuss
- 3. Find the sum of first 37 odd numbers
Options- A. 1369
- B. 1295
- C. 1388
- D. 1875 Discuss
- 4. Find the sum of first 84 even numbers
Options- A. 7140
- B. 7540
- C. 6720
- D. 8832 Discuss
- 5. Find the sum of cube of first 15 natural numbers.
Options- A. 15400
- B. 14400
- C. 16800
- D. 13300 Discuss
- 6. A number divided by 56 gives 29 as remainder. If the same number is divided by 8, the remainder will be ..
Options- A. 4
- B. 5
- C. 6
- D. 7 Discuss
- 7. On dividing a certain number by 357, the remainder is 39. On dividing the same number by 17, what will be the remainder?
Options- A. 5
- B. 3
- C. 7
- D. 6 Discuss
- 8. A number when divided by 5, leaves 3 as a remainder. What will be the remainder when the square of this number is divided by 5.
Options- A. 3
- B. 4
- C. 5
- D. 0 Discuss
- 9. A number when divided by a divisor leaves remainder of 24. When twice the original number is divided by the same divisor, the remainder is 11. What is the value of the divisor?
Options- A. 13
- B. 59
- C. 35
- D. 37 Discuss
- 10. The number 58129745812974 is divisible by
Options- A. 11
- B. 9
- C. 4
- D. None of these. Discuss
Number System problems
Search Results
Correct Answer: 9
Explanation:
Required unique digit = Unique digit in (7)754
= Unique digit in { (74)188 x 72 }
= Unique digit in ( 1 x 49 ) = 9
Correct Answer: 960
Explanation:
First 15 multiple of 8 are 8, 16, 24, ......, 120
Sum = 8 (1 + 2 + 3 + 4 ......+ 15)
= 8 [ n(n + 1) / 2]
= 8 x 15 x 8
960
Correct Answer: 1369
Explanation:
Sum of first n odd number = n2
Given, n = 37
? Required sum = 372
= 37 x 37
= 1369
Correct Answer: 7140
Explanation:
Sum of first n even numbers = n( n +1 )
Given n = 84
? Required sum = 84 ( 84 + 1 )
= 84 x 85
= 7140
Correct Answer: 14400
Explanation:
Sum of cubes of first n natural numbers = [ n(n+1) ]2
Given n = 15
? Required sum = [ ( 15 x 16 ) / 2 ] 2
= (15 x 8 )2
= 1202
= 14400
Correct Answer: 5
Explanation:
Let the number be N
According to question
N = 56k + 29
Then,
N = ( 8 x 7k ) + ( 8 x 3 ) + 5
Therefore if N will be divided by 8 the required remainder will = 5
Correct Answer: 5
Explanation:
Let the given number be N
Therefore N = 357k + 39
Then,
357 k + 39 = ( 17 x 21k ) + ( 17 x 2 ) + 5
? Required remainder = 5
Correct Answer: 4
Explanation:
Let the number be N.
Therefore N = 5k + 3
On squaring both sides, we get
N2 = ( 5k + 3)2
= 5( 5k2 + 6k +1 ) + 4
? On dividing x2 by 5, the remainder is 4
Correct Answer: 37
Explanation:
Let the divisor be x and quotient be y.
Then, the number = xy + 24
Twice the number = 2xy + 48
Now 2xy is completely divisible by x.
On dividing 48 by x remainder is x
? x = 48 - 11
= 37
Correct Answer: 11
Explanation:
We know that, a number is divisible by 11 when the sum of the difference between the sum of its digit at even places and sum of its digit at odd places is either 0 or the difference is divisible by 11.
So number is 58129745812974
Sum of digit at odd places = 4 + 9 + 1 + 5 + 7 + 2 + 8 = 36
Sum of digit at even places = 7 + 2 + 8 + 4 + 9 + 1 + 5 = 36
So, required difference = 36 - 36 = 0
? number is divisible by 11.
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