| Question | The radius of a circle is 20 cm. If the radius of this circle is decreased to 10 cm, then by what percentage will the area of the circle decrease? | |
| Type | multiple_choice | |
| Option | 60% | incorrect |
| Option | 75% | correct |
| Option | 35% | incorrect |
| Option | 50% | incorrect |
Solution : percentage ratio =
Required percentage =
