population in 1980 was 983 million; in 1990, it was 1,154 million. Compute the doubling

A population of bacteria loses half its population every 55 minutes.Initially the population is 50,000.How much time passes before there will be 30,000? (round to the nearest first decimal)

A wooden artifact from an ancient tomb contains 35 percent of the carbon-14 that is present in living trees. How long ago, to the nearest year, was the artifact made? (The half-life of carbon-14 is 5730 years.) years

A small gasoline shop engine develops 80 hp at 2000 rpm. At 2400 rpm its power output is increased by 20%. What actual horsepower does it produce at 2400 rpm? The engine produces hp at 2400 rpm. (Type a whole number or an exact decimal. If the decimal does not terminate, round to one decimal place.)