51.

Find the sum of $\frac{0.01 }{0.1}+\frac{0.1}{0.01}$

• 10.11

• 10.10

• 1.10

• 11.10

If ${\mathrm{x}}^2+\frac{1}{{\mathrm{x}}^2}$=66, then find the value of $\mathrm{x}-\frac{1}{\mathrm{x}}$

• 8

• 16

• 33

• 64

A number gets reduced to one-third when 48 is subtracted from it. What will be two-third of that number?

• 24

• 72

• 96

• None of these

The distance between two places is 12 km. A map scale is 1:25000. The distance between the two places on the map, (in cm) is

• 24

• 36

• 48

• 60

The reciprocal of $\frac{-3}{8}\times \left(\frac{-7}{13}\right)$ is

• $\frac{104}{21}$

• $\frac{-104}{21}$

• $\frac{21}{104}$

• $\frac{-21}{104}$

When half of a number is increased by 15, the result is 39. The sum of digits of the original number is

• 6

• 7

• 9

• 12

40% of (100 - 20% of 300) is equal to

• 16

• 20

• 64

• 140

If y = $\frac{\mathrm{x}-2}{\mathrm{x}+1}$, y= 1 , then x equals

• $\frac{\mathrm{y}+2}{1-\mathrm{y}}$

• $\frac{\mathrm{y}+2}{\mathrm{y}-1}$

• $\frac{\mathrm{y}-2}{\mathrm{y}+1}$

• $\frac{2-\mathrm{y}}{1-\mathrm{y}}$

The hundreds digit of a three-digit number is 7 more than the units digit. The digits of the number are reversed and the resulting number is subtracted from the original three-digit number. The units digit of the final number so obtained is

• 0

• 1

• 2

• 3

Rani, who is y yr old at present, is x yr older than Hamid. 15 yr ago, Hamid's age was $\frac{1}{4}$ of the age of Rani. Which of the following is true?

• 3y-4x= 45

• 2y-x= 15

• $\frac{\mathrm{y}}{\mathrm{x}}$-15= $\frac{1}{4}$

• 3x-4y= 45