Answer:
The first common multiple is 60
Step-by-step explanation:
The first common multiple can be found by making a list of multiples of each number and finding the first one that is the same:
12x1=12
12x2=24
12x3=36
12x4=48
12x5=60
15x1=15
15x2=30
15x3=45
15x4=60
Notice that 12x5=60 and 15x4=60
This is the first multiple they have in common, therefore 60 is the first common multiple.