SOLUTION: how many numbers between 150 and 300 are divisible by 7?

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Question 522654: how many numbers between 150 and 300 are divisible by 7?
Answer by Tatiana_Stebko(1539) About Me  (Show Source):
You can put this solution on YOUR website!
The smallest is 154, the biggest is 294
we can look at them like at an arithmetic progression
a%5B1%5D=154, d=7, a%5Bn%5D=294
a%5Bn%5D=a%5B1%5D%2Bd%2A%28n-1%29
294=154%2B7%2A%28n-1%29
7%28n-1%29=294-154
7%28n-1%29=140 divide by 7
n-1=20
n=20%2B1
n=21
Answer:21