Question

Which of the following expressions does not represent “increase a quantity n by 25%”?

A. n + 0.25n
B. (1 + 0.25)n
C. 125n
D. 1 1/4 n ( one and one forth n)

Answer 1

Option C) 125n is the expression that does not represent “increase a quantity n by 25%

Explanation:

The given expressions are for the quantity n which is increased by 25%.

• Let us consider that n = 100.
• The increase of n by 25 % is equal to 125.
• Check for each options by substituting n=100 and the expression gives 125 or not.
• Check which option does not represent the condition (increase of n by 25%)

Option A) n + 0.25n

Put n = 100,

⇒ 100 + 0.25(100)

⇒ 100 + 25

⇒ 125

So, option A) represents the given condition.

Option B) (1 + 0.25)n

Put n = 100,

⇒ (1+0.25) 100

Multiply 100 with each terms inside the bracket.

⇒ 100 + 25

⇒ 125

So, option B) represents the given condition.

Option C) 125n

Put n = 100,

⇒ 125 × 100

⇒ 12500

So, option C) does not represents the given condition.

Option D) 1 1/4 n

Put n = 100,

Convert the mixed fraction to proper fraction

⇒ (5/4) n

⇒ (5/4) 100

⇒ 500 / 4

⇒ 125

So, option D) represents the given condition.