Alex worked 5 hours
Step-by-step explanation:
Amount Alex earns per hour = $3
let the number of hours worked = h
Total amount earned = $15
Total amount earned = Amount Alex earns per hour × number of hours worked
15 = 3(h)
15 = 3h
divide both sides by 3:
15/3 = 3h/3
h = 5
Hence, Alex worked 5 hours