What does the smaller number next to numbers mean?

Plz i want answer and i would appreciate it is is a b c or d

Ricardo ran the 400 meter race 3 times his fastest time was 54.3 seconds his slowest time was 56.1 seconds if his average time was 55.0 seconds what was his time for the third race

Evaluate the expression for the given value of the variable. 5×(h+3) for h=7