## Numbers divisible by 3

1. The problem statement, all variables and given/known data
How many 3 digit numbers are divisibIe by 5?

2. Relevant equations

3. The attempt at a solution
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 Attempt to a solution?
 I don't get 136. How did you come up with that answer?

Recognitions:
Homework Help

## Numbers divisible by 3

I don't get 136 either. How did you get that?
 Recognitions: Homework Help Science Advisor There are 'roughly' 20 numbers in every 100 that are divisible by 5. There are 'roughly' 900 three digit numbers. So there are 'roughly' 180 three digit numbers divisible by 5. That's enough off from 136 to make me agree with Defennder and Tedjin. You must be wrong.
 5, 10, 15, 20, 25, 30 Its all the numbers that end in 5 or zero, and then ignore the last one (1000) because it had the temerity to posses 4 digits. As you start building the sequence, you see the rule easy enough.
 an=nth term of an AP (Arithmetic progression) a=1st term d=common difference Since the 1st 3 digit no. divisible by 5 is 100 a=100 the last 3 digit no. divisible by 5 is 995 an=995 common difference (d)=5 n=no. of 3 digit nos. divisible by 5 an=a+(n-1)d 995=100+(n-1)5 995-100=(n-1)5 895=(n-1)5 895/5=n-1 179=n-1 179+1=n n=180 Therefore, exactly (not roughly) 180 3 digit numbers are divisibe by 5 Absolutely correct Dick!!! @Amith2006 How did you get 136?!
 Admin Year that passed since the thread was started was enough to count these numbers using fingers.
 Aha that made me laugh, insane bump