If the angles of a quadrilateral are (3y + 10)^\circ, (2y + 30)^\circ, (y + 20)^\circ and 4y^\circ. Find the value of y.
A
66°
B
12°
C
30°
D
42°
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
Sum of angles in a quadrilateral = 360^\circ
\(\therefore\) (3y + 10) + (2y + 30) + (y + 20) + 4y = 360
10y + 60 = 360 \(\implies\) 10y = 300
y = 30^\circ
Source: Myschool Past Questions Archive (Record #54917)