Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Numerical Ability

Topic

Percentages

Question:

With reference to a number greater than one, the difference between itself and its reciprocal is 25% of the sum of itself and its reciprocal. By how much percent is the fourth power of the number greater than its square?

Options:

57.8

62.5

64.5

66.7

Correct Answer:

66.7

Explanation:

Let the no. = x

x - \(\frac{1}{×}\) = \(\frac{25}{100}\) (x + (\(\frac{1}{×}\))

x2 - 1 = \(\frac{1}{4}\) (x2 + 1 )

4x2 - 4 = x2 + 1

3x2 = 5

⇒ x2 = \(\frac{5}{3}\) & x4 = \(\frac{25}{9}\)

Required percentage = \(\frac{\frac{25}{9} -\frac{5}{3}}{\frac{5}{3}}\) × 100 = 66.7%