Answer:
First do the case in which none of the digits is 0.
There are 9 ways to choose the digit that repeats 3 times and 8 ways to pick the other, after this there are 4 ways to order the digits. So 9×8×4.
Now we look at the cases in which the digit 0 repeats 3 times. Clearly the 9 numbers are 1000,2000,3000,…,9000.
Lastly we look at the cases in which 0 appears once. There are 9 ways to pick the other digit and 3 ways to order.
So the final answer is 9×8×4+9+9×3.
Answer:
Step-by-step explanation:
D . Is the correct answer
Answer:
57
Step-by-step explanation:
57 is a composite number
Answer:
90 degrees
Step-by-step explanation:
All trapazoids are equal to 360 degrees.
so we can make an equation 2x+x+x=360 (the other corner would also be x because its an unknown value)
to simplify, 4x=360
you divide into both sides (360/4)
you get 90
