Sonam wants to calculate how many more seconds he has while he is awake.Suppose Sonam is 25 years old. He sleeps 8 hours per day. He estimates he will live to be 75 years old. Without using a calculator, estimate how many 'waking seconds' he has. Use your rounding skills to find the answer!
A. 3,000,000,000 (or 3 x 10^9 seconds) B. 2,000,000,000 (or 2 x 10^9 seconds) C. 1,000,000,000 (or 1 x 10^9 seconds) D. 4,000,000,000 (or 4 x 10^9 seconds)