What value of y would make AOB, a line in the figure, if ∠AOC=4y and ∠BOC=(6y+30).
In the figure, AOB is a line if ∠AOC+∠BOC=180∘ ⇒6y+30∘+4y=180∘⇒10y=180∘−30∘=150∘⇒y=150∘10=15∘∴y=15∘