Ah, thank you. your question truly made the most of sense.
Total fruits→120=4u
apples=30=1u
3u=90→banana and oranges
banana→1u
oranges→2u
oranges=60
To find the answer, use 
, and then use the equation 
To find it's half life.
Answer:
He should have added 0 to 8 and multiplied 1 by 8
Step-by-step explanation:
Multiples of 4: 4,8,12,16,20,24,28,32,36,40,44,48,52,56,60
12 24 36 and 48 are the only common factors
so 4 days
