Answer:
a. 5,040 ways
b. 210 ways
Explanation:
a) We want to pick 4 numbers out of 10 given that orders matter
If orders do matter, it will be a permutation problem
Mathematically;
n P r = n!/(n-r)!
In this case, n is 10 and r is 4
Thus, we have it that;
10 P 4 = 10!/(10-4)! = 5,040
b) if orders do not matter
It will be a combination problem
n C r = n!/(n-r)!r!
n = 10 and r = 4
10 C 4 = 10! /(10-4)!4!
= 210