Explanation:
To find what percent a first number is of second number, divide the first number by the second number and multiply by 100%.
To find what percent 16 is of 5, divide 16 by 5 and multiply by 100%.
16/5 * 100% = 3.2 * 100% = 320%
"Percent" literally means "per 100."
100% means 100 out of 100, and means an entire amount.
More than 100% percent means more than the entire amount.
5 hours was the estimated time. 100% of 5 hours is 5 hours, the entire amount. More than 100% is more than the entire amount, so it is more than 5 hours. 16 hours is certainly much more than 5 hours, and it is 320% of 5 hours.