9*13+n
I think that is correct, try and split up the question.
9*
A sum of a number AND 13
So that means that 9 is multiplying by the SUM (adding) of 13 and a number (n)
Q1: 479 001 600 ways
Explanation:
You have 12 people, 12 seats, ¹²P₁₂ ways in arranging them, or essentially 12! ways
Q2: 1 036 800 ways
Explanation:
Let's break it up into two cases.
Case 1: BGBGBGBGBGBG
Case 2:GBGBGBGBGBGB
Let's deal with case 1, because case 2 will pop out. There are ⁶P₆ ways in sorting out the boys and ⁶P₆ ways in sorting out the girls, so for case 1, we'd have (⁶P₆)² ways in sorting out boys and girls in case 1.
This is exactly the same in case 2, so it'd be (⁶P₆)² ways in sorting out girls and boys in case 2.
So, (⁶P₆)² + (⁶P₆)² ways = 1 036 800 ways if they alternate
Formula:
Total hours ÷ hour per day
14 ÷ 3.5 = 4.
The answer is 4.
He commuted 4 days for the city.
