1. number is even, so last digit must be 0 or 4
That leaves 7 other digits, with 3 5's and 3 7's.
So, we have 7!/3!3! * 2 = 280
How did you get 240?
each term in the triangle is the sum of the two terms above. So, we have
t(7,3)
1. How many eight digit even numbers are possible with the digits 7 5 4 5 7 5 0 7?
Is the correct answer 240? If not, please explain.
2. Express t(6,3) + t(6,2) as a single term from Pascal's Triangle.
*The (6,3) and (6,2) are subscripts of t.
3 answers
Why do you multiply 7!/3!3! by 2?
because the last digit can be chosen in 2 ways: 0 or 4.