2007-06-13 09:37:17 · 13 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
20! / 18!
= (20 * 19 * 18!) / 18!
= 20 * 19
= 380
2007-06-20 06:06:02 · answer #1 · answered by topsyk 3 · 0⤊ 0⤋
We can write 20!as 20*19*18! /18! =20*19 =380
2007-06-20 19:16:37 · answer #2 · answered by Shashank 1 · 0⤊ 0⤋
=20*19=380
2007-06-21 04:35:22 · answer #3 · answered by Anonymous · 0⤊ 0⤋
20!/18! = (20*19*18*17*...*3*2*1) / (18*17*16*...*3*2*1)
Do you see that the denominator cancels out and we get 20*19 left over in the numerator? So the answer is 380.
2007-06-21 04:14:36 · answer #4 · answered by corgi 3 · 0⤊ 0⤋
20*19=380
2007-06-17 16:03:08 · answer #5 · answered by Vikas 3 · 1⤊ 0⤋
Once you understand factorials (the exclamation points), this is actually easy.
20! = 20*19*18*17*...*3*2*1
18! = 18*17*...*3*2*1
Now when you have a fraction with multiplication in it, you can reduce it by canceling (dividing) things from the numerator and the denominator. In this case,
20!/18! = 20*19*(18*17*...*3*2*1)/(18*17*...*3*2*1)
= 20*19
= 380
2007-06-13 09:42:54 · answer #6 · answered by math guy 6 · 0⤊ 1⤋
Answer:
20!/18!=19*20=380
(x! means 1*2...*(x-1)*x)
I hope I helped you.
2007-06-20 08:50:25 · answer #7 · answered by Diablo 3 · 0⤊ 0⤋
20! = (1 * 2 *.....18) * 19 * 20 = 18! * 19 * 20. Therefore, 20!/18! = 19 * 20 = 380
2007-06-13 10:00:04 · answer #8 · answered by Steiner 7 · 0⤊ 1⤋
20(19)=380
2007-06-20 17:36:18 · answer #9 · answered by Math Master 2 · 0⤊ 0⤋
20! = 20x19x18x17x etc.
18! = 18x17x etc
cancel 18! from the fraction leaving 20x19/1=380
2007-06-13 09:44:39 · answer #10 · answered by skipper 7 · 0⤊ 1⤋