The area (in sq. units) of the region enclosed by the ellipse $16x^2 + 25y^2 = 400$ is

$20 π$

The correct answer is Option (4) → $20 π$

Given ellipse

$16x^2+25y^2=400$

Divide by $400$

$\frac{x^2}{25}+\frac{y^2}{16}=1$

Hence $a=5,\;b=4$

Area of ellipse

$=\pi ab$

$=\pi\times5\times4$

$=20\pi$

The area enclosed by the ellipse is $20\pi$ square units.