What is the percent of change for a radio that was priced at $20 but is not on sale for $15?

Teams of 4 are competing in a 1/4 mile relay race. each runner must run the same exact distance. what is the distance each teammate runs?

15m is what percent of 60m; 3m; 30m; 1.5 km? the last one is km not m

Identify the initial amount a and the growth factor b in the exponential function. a(x)=680*4.3^x