Fear factor!!

Level 2

How many positive factor are there for 10! Factorial of 10?


The answer is 270.

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

2 solutions

Michael Diao
Feb 2, 2014

The prime factorization of 10 ! 10! is 2 8 × 3 4 × 5 2 × 7. 2^8\times3^4\times5^2\times7. We have 9 9 ways to choose a power of 2 2 for a factor ( 8 + 1 8+1 ), 5 5 ways to choose a power of 3 3 ( 4 + 1 4+1 ), 3 3 ways for 5 5 ( 2 + 1 2+1 ), and 2 2 ways for 7 ( 1 + 1 1+1 ). Thus, the number of factors of 10 ! 10! is 9 × 5 × 3 × 2 = 270 . 9\times5\times3\times2=\boxed{270}.

Extra: This way of finding the number of factors of a number is known as the Formula of Factors.

Read more here: Number of Factors of an Integer

Mohamed Abdelaaty
Feb 11, 2014

Let's factorize 10! = 1 2 3 4 5 6 7 8 9 10 = 1*2*3*4*5*6*7*8*9*10=

2 8 3 4 5 2 7 2^8*3^4*5^2*7

To get the number of factors we take all exponents and add one to them, then multiply them.

9 5 3 2 = 270 . 9*5*3*2 = \boxed{270}.

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...