there is 6 letter d,f,g,h,r,t.then how many word of 2 letter can be form through these letters?  Choices:
A) 720	B) 360	C) 48	D) 30	E) 24
it will comes like 6P2   6!/4!=(1*2*3*4*5*6)/1*2*3*4=30   answer 30
<result>D</result>
there is 6 letter d,f,g,h,r,t.then how many word of 2 letter can be form through these letters?