Question

How many degrees are there in an angle which equals one-fifth of its supplement?

• A. 15°
• B. 30°
• C. 75°
• D. 150°

Answer 1

The correct option is B

30°

Let the angle be x. Given that,

x = $\frac{1}{5}$(180${}^{\circ }$ - x)

So, 5x = (180${}^{\circ }$ - x)

⇒ 6x = 180${}^{\circ }$

⇒ x = 30${}^{\circ }$