Question

What is the percentage decrease in the number of cattle if the ratio between now and an year earlier is 1:2 ?

• A. 50%
• B. 100%
• C. 150%
• D. 200%

Answer 1

The correct option is A 50%

Let us take the final value to be $x$.
The initial value is $2x$.

So, percentage increase
= $\frac{Finalvalue-Initialvalue}{Initialvalue}\times 100\%$
= $\frac{1-2}{2}\times 100$
= $-50\%$

As the sign is negative, so the percentage of the number of cattle decreased by $50\%$.