Saturday

December 20, 2014

December 20, 2014

Posted by **Joe** on Tuesday, May 31, 2011 at 12:41am.

- Math -
**MathMate**, Tuesday, May 31, 2011 at 7:12amHow many numbers are divisible by 5 between 1 and 20?

- Math -
**joe**, Tuesday, May 31, 2011 at 10:18am20,15,10, and 5 are all divisible by 5. so 4. Is that how you solve for the amount of terminal zero's?

- Math -
**joe**, Tuesday, May 31, 2011 at 10:20amuh oh my mistake. I missed a key part of the question. the question is..... How many terminal zeros are at the end of (20!)^2?

- Math -
**MathMate**, Tuesday, May 31, 2011 at 1:23pmThe way we can get a terminal zero in a product depends on two factors (no pun intended), 2 and 5.

There are plenty of two's between 1 and 20, namely we get three of them in 8=2^3, and 16=2^4.

Therefore the governing factor is the number of 5's, which when combined with 2 gives a terminal zero.

If there are four 5's between 1 and 20, then 20! will have 4 terminal zeroes.

As you probably figured it out, squaring doubles the number of terminal zeroes.

So if 20! has 4, then (20!)^2 should have???

Note: watch out if and when you come to 25!

25=5^2, so counts as 2 factors of 5.

- Math -
**joe**, Wednesday, June 1, 2011 at 12:34amalright thankyou.

- Math -
**MathMate**, Wednesday, June 1, 2011 at 8:07amYou're welcome!

- Math -
**jane**, Friday, June 3, 2011 at 5:05amyou go to sunland dont you?

**Answer this Question**

**Related Questions**

7th grade, math - Can someone explain the steps to solve this problem? If a ...

Decartes Rule of Signs - Could you explain to me decartes Rule of signs? Here ...

Math - An appliance company has a warehouse and two terminals. To minimize ...

Math terminal zeroes - If a number ends in zeroes, the zeroes are called ...

Math - I just wanted to double check that I am correct. 1.Find the zeros for the...

math - f(x)= x^3 - 2x^2 - 21x - 18 all possible rational zeros # of possible ...

Math - State the number of positive real zeros, negative real zeros, and ...

math - Karen says, "When I have a factor with exactly 2 zeros at the end, my ...

math - usethe rational zero theorem to find all real zeros of the polynomisl ...

Math Problem (please help) - Find all the zeros of the function. When there is ...