Question

Wilbur has homework assignments in seven subjects. He only has time to do five of them.

Answer 1

• 21 ways

Explanation:

Given

• Wilbur has 7 subjects' homework
• He can only do 5 of them

Combination Formula

• ⁿCₓ = n! / (n - x)! x!

Number of possible ways

• ⁷C₅ = 7! / 2! x 5!
• ⇒ 7 x 6 x 5! / 2! x 5!
• ⇒ 7 x 6 / 2
• ⇒ 7 x 3
• ⇒ 21 ways