Question

A complete cycle of a traffic light takes $60\, seconds$. During each cycle the light is green for $25\, seconds$, yellow for $5 \,seconds$ and red for $30\, seconds$. At a randomly chosen time, the probability that the light will not be green, is

• A. $\frac{1}{3}$
• B. $\frac{1}{4}$
• C. $\frac{4}{12}$
• D. $\frac{7}{12}$

Answer 1

Answer: (D)

$\frac{7}{12}$

Answer 2

$\therefore$ Required probability
$=\frac{30+5}{60}$
$=\frac{7}{12}$