A deep sea exploring ship is pulling up a diver at the rate of 20 feet per minute. The diver is a hundred feet below sea level. How deep was the diver 3 minutes ago?

60 Feet Deep

Step-by-step explanation:

It says that you go 20 feet a minute and you 3 minutes ago would be 20x3

6.25%

Step-by-step explanation:

Percent error is calculated by taking the difference of measured value and correct value divided by correct value and multiplied by 100%.

Mathematically,

Percent error = (correct value - measured value)/correct value  * 100%

in the problem given

measured value = 75 degrees Celsius

correct value = 80 degrees Celsius ( as given in reference book)

thus,

Percent error = (80 - 75)/80 * 100%

Percent error = (5/80 )* 100% = 6.25%

Percent error calculated by him is  6.25%.