You can enter your answer as a formula, or you can enter your final calculated result.
Here you can see how to enter your solution as a formula:
Combination
"A choose B". Enter: Aob or AüB (Example: 10o2 or 10ü2 =

)
Factorial
Enter: a! (Example: 5! = 1*2*3*4*5)
Exponent
Enter: a^b (Example: 2^3 = 2
3)
Addition
Enter: a+b (Example: 2+3)
Multiplication
Enter: a*b (Example: 2*3)
Division
Enter: a/b (Example: 2/3)
Here are two more small examples:
Problem 1: In a fruit shop for a special offer, they pack 10 pieces of fruit from 4 different types. How many different fruit bags can exist?
Solution:

or
Problem 2: In a cinema salon there are 15 free seats left. In how many different ways can 3 people take place?
Solution:

or