20
Q:

# 476 ** 0 is divisible by both 3 and 11.The non zero digits in the hundred's and ten's places are respectively:

 A) 6 and 2 B) 8 and 2 C) 6 and 5 D) 8 and 5

Explanation:

Let the number  be 476ab0

476ab0 is divisible by 3

=> 4 + 7 + 6 + a + b + 0 is divisible by 3

=> 17 + a + b is divisible by 3 ------------------------(i)

476ab0 is divisible by 11

[(4 + 6 + b) -(7 + a + 0)] is 0 or divisible by 11

=> [3 + (b - a)] is 0 or divisible by 11  --------------(ii)

Substitute the values of a and b with the values given in the choices and select the values which satisfies both Equation 1 and Equation 2.

if a=6 and b=2,

17 + a + b = 17 + 6 + 2 = 25 which is not divisible by 3 --- Does not meet equation(i).Hence this is not the answer

if a=8 and b=2,

17 + a + b = 17 + 8 + 2 = 27 which is divisible by 3 --- Meet equation(i)

[3 + (b - a)] = [3 + (2 - 8)] = -3 which is neither 0 nor divisible by 11---Does not meet equation(ii).Hence this is not the answer

if a=6 and b=5,

17 + a + b = 17 + 6 + 5 = 28 which is not divisible by 3 --- Does not meet equation (i) .Hence this is not the answer

if a=8 and b=5,

17 + a + b = 17 + 8 + 5 = 30 which is divisible by 3 --- Meet equation 1

[3 + (b - a)] = [3 + (5 - 8)] = 0 ---Meet equation 2

Since these values satisfies both equation 1 and equation 2, this is the answer

Q:

In math questions answers each questions are solved with explanation. The questions are based from different topics. Care has been taken to solve the questions in such a way that students can understand each and every step

1. Which is greater than 4?

(a) 5,

(b) -5,

(c) -1/2,

(d) -25.

 A) 5 B) 20 C) 2 D) 3

Explanation:

Solution:

5 greater than 4.

1 98
Q:

Which of the following is the largest?

 A) 12/49 B) 7/30 C) 13/56 D) 11/46

Explanation:

In the given options,

12/49 can be written as 1/(49/12) = 1/4.083

7/30 can be written as 1/(30/7) = 1/4.285

13/56 can be written as 1/(56/13) = 1/4.307

11/46 can be written as 1/(46/11) = 1/4.1818

Here in the above,

1/4.083 has the smallest denominator and so 12/49 is the largest number or fraction.

3 316
Q:

7, 16, 36, 78, 144, ?

which number come in place of question mark

 A) 168 B) 196 C) 222 D) 256

Explanation:

16 712
Q:

Which of the following is a rational number?

 A) 0.241 B) 1.732 C) 4 D) All of the above

Explanation:

Any number which can be expressed as a fraction of two integers like P & Q as P/Q where Q is not equal to zero.

Every integer is a rational number since Q can be 1.

Hence, in the given options, 4 can be expressed as a simple fraction as 4/1. And all other options cannot be expressed as fractions.

Hence, 4 is a rational number in the given options.

3 576
Q:

Which expression is equivalent to $i233$?

 A) i B) 1 C) -i D) -1

Explanation:

We know that,

6 1868
Q:

The product of a number and its multiplicative inverse is

 A) 1 B) 0 C) -1 D) Infinity

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.

2 1204
Q:

25 divided by 7

 A) 3.571 B) 35.71 C) 0.351 D) 0.0357

Explanation:

Here we have 25 divided by 7.

25 will not go directly in 7

Hence, we get the result in decimals.

25/7 = 3.571.

4 1064
Q:

Which of the following is not a prime number?

 A) 5 B) 11 C) 21 D) 37

Explanation:

A prime number is a whole number greater than 1 whose only factors are 1 and itself.

Factors of 5 are 1, 5

Factors of 11 are 1, 11

Factors of 21 are 1, 3, 7, 21

Factors of 37 are 1, 37.

Hence, according to the definition of a prime number, 21 is not a prime number as it has more than two factors.