(A) What fraction of the rectangle is covered by the circles?

(B) What fraction of the rectangle is covered by the circles?

(A) Suppose the radius of each circle is $r$.

Height of rectangle $= 2r$

There are 3 circles side by side,

so length $= 6r$

Area of rectangle $= 6r \times 2r = 12r^2$

Area covered by 3 circles $= 3\pi r^2$

Fraction covered: $\frac{3\pi r^2}{12r^2} = \frac{\pi}{4}$

Fraction covered $= \frac{\pi}{4}$

(B) Let radius of each circle be $r$.

Height of rectangle = $2r$

Four circles are placed side by side, so the length is $8r$.

Area of rectangle = $8r \times 2r = 16r^2$

Area covered by 4 circles = $4\pi r^2$

$$\text{Fraction covered: } \frac{4\pi r^2}{16r^2} = \frac{\pi}{4}$$

$$\text{Fraction covered} = \frac{\pi}{4}$$