What is the sum of all of the four-digit positive integers that can be written with the digits 1, 2, 3 and 4 if each digit must
be used exactly once in each four-digit positive integer?
1 answer:
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
You might be interested in
Consider all parabolas:
1.
When x=-3, y=-1, then the point (-3,-1) is vertex of this first parabola.
2.
When x=-4, y=-4, then the point (-4,-4) is vertex of this second parabola.
3.
When x=2.5, y=20.25, then the point (2.5,20.25) is vertex of this third parabola.
4.
When x=3.5, y=19.25, then the point (3.5,19.25) is vertex of this fourth parabola.
5.
When x=-1.75, y=-1.125, then the point (-1.75,-1.125) is vertex of this fifth parabola.
6.
When x=2, y=13, then the point (2,13) is vertex of this sixth parabola.
Answer:
Step-by-step explanation:
this is the same concept basically as simplifying into
. You can see that the denominator is in front of the radical and that any numbers in the numerator are the power of the number underneath.