Answer:
70%
Step-by-step explanation:
I'm sorry but I don't really know how to explain it other than 70% of 30 is 21 so that means that 30% of the students turned their essay in on time.
(sorry for not being able to explain it but I hope it helped)
hopefully this will help :)
Let say the number is 0.5
Then, sum of this number will be 0.5+0.5=1
Now two is twice of 1.
Hence, it proved to be correct.
And difference between 5 and 1 is 4 which is less than 12. It also match the question condition.
Answer: The number is 1.