Liam, a 19th century cowboy, carries an 1847 Colt single action 6 shooter revolver. So proficient is

Liam, a 19th century cowboy, carries an 1847 Colt single action 6 shooter revolver. So proficient is he with this weapon that when he fires all 6 shots in a row, the time between the first bullet and the last is 40 seconds. How long would it take him to fire 4 shots?

We set up a proportion of shots to seconds where s is the number of seconds it takes to fire 4 shots:
6/40 = 4/s

Using our proportion calculator, we get:
s = 26.67