0
Q:

# 3x + y = 19  and x + 3y = 1. Find the value of 2x + 2y

 A) 20 B) 18 C) 11 D) 10

Explanation:

To solve a pair of simultaneous equations such as those given we can add or subtract them.

Adding we get 4x + 4y = 20

Therefore 2x + 2y = 10

Q:

Which expression is equivalent to ${\mathbf{i}}^{\mathbf{233}}$?

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

Explanation:

We know that,

0 59
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.

0 82
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.

1 101
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.

1 91
Q:

What are the Multiples of 4?

The Multiples of 4 are 4, 8, 12, 16, 20, 24, 28, 32, 36, 40 upto 40. Mutiples of 4 means which can be divided by 4 leaving remainder '0'.

Common Multiples of 4 & 6 are 12, 24, 36, 48, 60 upto 60.

605
Q:

The sum of three consecutive odd numbers is 93. What is the middle number?

 A) 31 B) 33 C) 29 D) 27

Explanation:

Let the three consecutive odd numbers be x, x+2, x+4

Then,

x + x + 2 + x + 4 = 93

=> 3x + 6 = 93

=> 3x = 87

=> x = 29 => 29, 31, 33 are three consecutive odd numbers.

Therefore, the middle number is 31.

7 1228
Q:

How many numbers up to 300 and 700 are divisible by 2, 3 and 7 both together ?

 A) 7 B) 9 C) 11 D) 5

Explanation:

LCM of 2, 3, 7 is 42.

=> (700 – 300)/42 = 9  22/42 => 9 Numbers.

15 2681
Q:

In a triangle ABC, angle 'a' is the smallest one & A+7B = 112. Find the range of value 'c' ?

 A) 138 to 164 B) 125 to 147 C) 148 to 158 D) 152 to 164