Correct Answer: 8

Explanation:

9321 = 3 x 13 x 239 = 31 x 13 1 x 239 1 ; add one to all the powers ie.,

(1+1) x (1+1) x (1+1)= 8 ;

we get eight factors.

Correct Answer: 1

Explanation:

The mutiplicative inverse of a number is nothing but a reciprocal of a number.

Now, the product of a number and its multiplicative inverse is always equal to 1.

 

For example :

Let the number be 15

Multiplicative inverse of 15 = 1/15

The product of a number and its multiplicative inverse is = 15 x 1/15 = 1.

Correct Answer: 5

Explanation:

By trial and error method, we get
2880/3 = 960 is not a perfect square
2880/4 = 720 is not a perfect square
2880/5 = 576 which is perfect square of 24
Hence, 5 is the least number by which 2880 must be divided in order to make it into a perfect square.

Correct Answer: 152 to 164

Explanation:

A+7B=112

it is clear that A = 14, then it becomes A>=B, but A is smallest angle) given
so, range of A is 0.0001 to 13.9999 ( I am taking upto 4 decimal places)
so, range of B becomes 14 to 16 ( after rounding off to 4 decimal places)
so, range of C becomes 152 to 164 ( after rounding off to 4 decimal places)

Correct Answer: i

Explanation:

We know that,

$$\begin{gathered} i 2 = - 1 \\ i 3 = i 2 x i = - 1 x i = - i \\ i 4 = i 2 x i 2 = - 1 x - 1 = 1 \\ Hence , i 233 = i 4 x 58 + 1 = i 232 x i 1 = 1 x i = i \end{gathered}$$

Correct Answer: 28

Explanation:

Let the original number is 82 i.e 8 + 2 = 10 and when the digits are reversed i.e 28
The difference is 82 - 28 = 54 i.e, the number is decreased by 54.

Correct Answer: 400

Explanation:

The value of 4 in 475 means the place value of 4 in 475 and not its face value. Face value means the digit itself though it is at any place in the given number. But place value means the value of digit in its place in the given number.

 

Here the place value of 4 in 475 can be determined by as 4 is in 100's place in 475.

Hence, the place value of 4 in 475 is 4x100 = 400.

Correct Answer: 1001

Explanation:

Here by trial and error method, we can obseve that

404404 = 404 x 1001; 415415 = 415 x 1001, etc.

So, any number of this form is divisible by 1001.

Correct Answer: 555681

Explanation:

Given number is 987 = 3 x 7 x 47.

So, required number must be divisible by each one of 3, 7, 47.

None of the numbers in 553681 and 555181 are divisible by 3. While 556581 is not divisible by 7.
Correct answer is 555681.

Correct Answer: 9

Explanation:

Last digit for the power of 6 is 6 (always)

Power cycle of 7 is 7, 9, 3, 1.

Now 467/4 gives a remainder of 3

Then the last digit is 7 3 = 3

Last digit is 6 + 3 = 9.