The document describes the times of three students - Isabel, Drewkel, and Estrella - running in a relay race. It provides their individual times and states the total time for the race was 21 minutes and 18 seconds. It then shows the calculation to determine the time of the fourth student by subtracting the known times from the total.

1. isabel ran 5 min and 19 sec
drewkel ran 3 min and 52 sec
estrella ran 6 min and 47 sec
if the total amout they ran was 21 min and 18 sec
how long did the 4 student run in the relay race?
Solution
Isabel time + drewkel time + estrella time + ? = total time Fourth student time = 21
min and 18 sec - (5 min and 19 sec+3 min and 52 sec+6 min and 47 sec) = 5 minutes and 20
minutes Fourth student time = 21*60+18 sec - (5*60+19 sec+3*60+52 sec+6*60+47 sec) = 5
minutes and 20 minutes