Question

Which calculation could not be used to find the percentage change

Answer 1

Answer:

Option (B).

Step-by-step explanation:

Percentage change between two numbers a and b can be calculated by the formula,

% change = $\frac{|b-a|}{a}\times 100$

Where, (b - a) = Change in values

a = Initial value

If a = 16 and b = 20

Percentage change between 16 and 20 will be,

= $(\frac{20-16}{16})\times 100$

= $\frac{4}{16}\times 100$

= 25%

If a = 20 and b = 16,

Percentage change = $\frac{|16-20|}{20}\times 100$

                                 = 20%

Therefore, %change between 16 and 24 may be 16% or 20%.

Option (A),

$\frac{20-16}{16}\times 100$ = 25%

Option (B),

$\frac{20}{16}-1\times 100$ = 1.25 - 1 × 100

                   = 1.25 - 100

                   = -98.75%

Option (C),

$100\times \frac{1}{4}$ = 25%

Option (D),

$\frac{(20-16)}{20}\times 100$ = 20%

Therefore, we can not use the calculation used in Option (B).