A20-a18=a1+19d-a1-17d=2d =281-97
so
d=92
Answer: Hence, our required probability is 
Step-by-step explanation:
Since we have given that
Numbers in a lottery = 60
Numbers to win the jackpot = 7 numbers
We need to find the probability to hit the jackpot:
So, our required probability is given by

This is a combination problem as we need to select 7 numbers irrespective of any arrangements.
Hence, our required probability is [tex]\dfrac{1}{386206920}[/tex
4/15 because it can't be reduced any more. I hope this helps you out! :D