<em>So</em><em> </em><em>the</em><em> </em><em>right</em><em> </em><em>answer</em><em> </em><em>is</em><em> </em><em>8</em><em>/</em><em>5</em>
<em>Look</em><em> </em><em>at</em><em> </em><em>the</em><em> </em><em>attached</em><em> </em><em>picture</em>
<em>Hope</em><em> </em><em>it</em><em> </em><em>will</em><em> </em><em>help</em><em> </em><em>you</em>
<em>Good</em><em> </em><em>luck</em><em> </em><em>on</em><em> </em><em>your</em><em> </em><em>assignment</em>
Answer with explanation:
Number of four digit numbers using four distinct digit
=Unit placed can be filled in four ways * Tens place can be filled in Three ways * Hundreds place can be filled in 2 ways * Thousand Place can be filled in a single way
=4*3*2*1
=24 distinct numbers
Sum of all four , four digits numbers using 1,2,3,4
= (If we keep 4 at unit place +Keeping 3 at unit place +Keeping 2 at unit place+Keeping 1 at unit place)×6+At tens place (2*2+3*2+1*2+4*2+2*2+1*2+1*2+3*2+4*2+2*2+3*2+4*2)+At hundred's place (2*2+3*2+1*2+4*2+2*2+1*2+1*2+3*2+4*2+2*2+3*2+4*2)+At thousand's Place(2*2+3*2+1*2+4*2+2*2+1*2+1*2+3*2+4*2+2*2+3*2+4*2)
=(24+18+12+6)Unit place+(60)Ten's place +(60)Hundred's place+(60)Thousand's Place
=66660
