Question

You are running late for work. There are 4 traffic signals on your way to work, and if you make all of them,

you will be on time. If you have a 60% chance of making each one, independent of whether or not you made

the previous one, what is the probability that you will make it to work on time?


A. 81/625


B. 64/340


C. 32/125


D. 68/421


E. 25/525

Answer 1

Answer: A. 81/625

Explanation:

From the question, we are informed that there are 4 traffic signals on ones way to work, and there's a 60% chance of making each one, independent of whether or not the previous one is made.

The probability that one will make it to work on time will be to multiply 60% for the 4 period. This will be:

= 60% × 60% × 60% × 60%

= 60/100 × 60/100 × 60/100 × 60/100

= 3/5 × 3/5 × 3/5 × 3/5

= 81/625