Answer:
both watered on the same day, If we multiply 18 by any number such as 2,3,4,5 we can find the next soonest date that they will both be watered on. 18*2,3,4,5 30,2,3,4,5
18*2,3,4 are not multiples of 30, 18*5 is 90
30*2 is not a multiple of 18, 30*3 is 90
Now we know the next closest date they will be watered again is 90 days from now.
Step-by-step explanation: