Question

How many parts should be shaded in the figure B to make it represent the same fraction as the unshaded part of the figure A ?

Answer 1

Figure A is divided into four equal parts, out of which, one is shaded.
$\Rightarrow$ Figure A represents $\frac{1}{4}$. (1 mark)
Figure B is divided into twenty equal parts.
Here, we need a fraction which is equivalent to the fraction $\frac{1}{4}$ and having 20 as the denominator since figure B has twenty par (1 mark)
$\Rightarrow \frac{1}{4}=\frac{x}{20}$
$\Rightarrow 4x=20$
$\Rightarrow x=5$ (1 mark)
Therefore, the ratio equivalent to ratio $\frac{1}{4}$ is $\frac{5}{20}$.
So, 5 parts should be shaded in figure B. (1 mark)