Question 1

Given interchanges : Signs + and - , numbers 4 and 8.

Accepted Answer

On interchanging + and - and 4 and 8 in (b), we get the equation as 8 + 4 - 12 = 0 or 12 - 12 = 0 or 0 = 0, which is true.

Question 2

If × stands for 'addition', ÷ stands for 'subtraction', + stands for 'multiplication' and-stands for 'division', then 20 × 8 ÷ 8 - 4 + 2 = ?

Accepted Answer

By the Given data , We have the expression: 20 + 8 - 8 ÷ 4 × 2 = 20 + 8 - 2 × 2 = 20 + 8 - 4 = 24.

Question 3

Given intercharges : Signs + and x and numbers 4 and 5.

Accepted Answer

On interchanging + and x and 4 and 5 in (c), we get the equation as 4 + 5 x 20 = 104 or 104 = 104, which is true.

Question 4

Select the correct set of symbols which will fit in the given equation? 5 0 3 5 = 20

Accepted Answer

Clearly 5 - 0 + 3 X 5 = 20

Question 5

If × means ÷, - means ×, ÷ means + and + means- than (3 - 15 ÷ 19) × 8 + 6 = ?

Accepted Answer

By the given data, we have the expression : (3 × 15 + 19) ÷ 8 - 6 = (45 + 19) ÷ 8 - 6 = 64 ÷ 8 - 6 = 8 - 6 = 2

Question 6

12:30 :: 14: ?

Accepted Answer

Here 12 x 2.5 = 30 In the same way 14 x 2.5 = 35

Question 7

If Q means 'add to', J means 'multiply by', T means 'substract from' and K means 'divide by' then 30 K 2 Q 3 J 6 T 5 = ?

Accepted Answer

Using Correct Symbols , We have : Given expression = 30 / 2 + 3 x 6 - 5 = 15 + 18 - 5 = 28

Question 8

In a group of buffaloes and ducks the number of legs are 24 more than twice the number of heads. What is the number of buffaloes in the group ?

Accepted Answer

Let the number of buffaloes be x and number of ducks be y. Now, number of heads = x+y Number of legs = 4x+2y .......(1) But given that legs = 2(x+y)+24 ......(2) solving (1) & (2),we get 4x+2y=2x+2y+24 --> x=12. Therefore number of buffaloes =12

Question 9

In a cricket match, five batsmen P, Q, R, S and T scored an average of 36 runs. S Scored 5 more than T; T scored 8 fewer than P; Q scored as many as S and T combined; and Q and R scored 107 between them. How many runs did T score ?

Accepted Answer

Let the runs scored by P, Q, R, S and T be a, b, c, d and e From given data, a + b + c + d + e = 36 x 5 = 180 b + c = 107 Let a = x e = x-8 d = x-3 now 3x - 11 + 107 = 180 3x = 84 x = 28 e's score = 28-8 = 20

Question 10

The solution of 3(2u + v) = 7 uv and 3(u + 3v) = 11 uv is _____

Accepted Answer

Using Trial and error method, From the options u = 1, v = 3/2 satisfies both the equations.

Question 11

What approximate value will come in place of question mark (?) in the following question ? (49.001)2 = ?

Accepted Answer

Given (49.001)2 = ? => =~ 49 x 49 =~ 2401 =~ 2400

Question 12

What should come in place of the question mark(?) in the following questions ? 316 + 412 - 223 - 11112 = ?

Accepted Answer

? = (3 + 4 - 2 - 1) + ( 1/6 + 1/2 - 2/3 - 11/12) = 4 + [(2+6-8-11)/12] = 4 - (11/12 )= 31/12.

Question 13

A sum of Rs.1890 has to be used to give 9 prizes to the customers of a super market for their overall academic purchases. If each prize is Rs.30 less than its preceding price, what is the least value of the price ?

Accepted Answer

Let the least value of the prize = Rs. x Then the next value of the prize is x+30 , x+60, x+90, ....x+240. Given total amount of cash prizes = Rs.1890 --> x + (x+30) + (x+60) + (x+90) + ....+ (x+240) = 1890 --> 9x + (30 + 60 + 90 + 120 + 150 + 180 + 210 + 240) = 1890 --> 9x + 30(1 + 2 + 3 + 4....+ 8) = 1890 --> 9x + 30(36) = 1890 --> 9x = 810 --> x=90 Hence the least value of the prize x=90

Question 14

The value of -4-(-10) is how much greater then the value of -10-(-4) ?

Accepted Answer

-4-(-10) = -4+10 = 6 -10-(-4) = -10+4= -6 Therefore, 6-(-6) = 6+6 = 12

Question 15

Find the quadratic equations whose roots are the reciprocals of the roots of 2x2+5x+3 ? A) 3x2+5x+2=0 B) 5x2+3x+2=0 C) 3x2-5x-2=0 D) None

Accepted Answer

The quadratic equation whose roots are reciprocal of 2 x 2 + 5 x + 3 = 0 can be obtained by replacing x by 1/x. Hence, 2(1/x)(1/x)+ 5(1/x) + 3 = 0 => 3 x 2 + 5 x + 2 = 0

Question 16

The last two digits of 2151415 ?

Accepted Answer

Unit digit of this expression is always 1 as the base ends with 1. For the tenth place digit we need to multiply the digit in the tenth place of the base and unit digit of the power and take its unit digit. i.e, tenth place digit in 2151 is 5 and tenth place digit in power 415 is 1 And the units digit in the product of 5 x 1 = 5 Therefore, last two digits of 2151 415 is 51.

Question 17

Find the Value of ? 5.112.2+5.553.3+6.31.4+7.22.001 = ? x 3.34

Accepted Answer

This can be done in a method called Approximation. Now, 5 2 + 6 3 + 6 + 7 2 = ? x 3 . 34 25 + 216 + 6 + 49 = ? x 3 . 34 296 = ? x 3 . 34 ? = 296 3 . 34 = 88 . 622 ≅ 89

Question 18

Can you Solve 7 + 7 ÷ 7 + 7 x 7 + 7 - 7 ÷ 7 + 7 x 7 =

Accepted Answer

7 + 7 ÷ 7 + 7 x 7 + 7 - 7 ÷ 7 + 7 x 7 = 7 + 1 + 49 + 7 - 1 + 49 = 8 + 56 + 48 = 56 + 56 = 112

Question 19

3 x 3 + 3 - 3 + 3 = ?

Accepted Answer

Using BODMAS law, 3 x 3 + 3 - 3 + 3 = 3 x 3 = 12 = 12 + 3 - 3 + 3 = 9 + 3 = 12 Hence, 3 x 3 + 3 - 3 + 3 = 12.

Question 20

5068 / 37 x 4 = ?

Accepted Answer

? = 5068 x 4/37 ? = 548

Mathematical Operations Questions