you spin a spinner once, your numbers are 9,8,7,6. What is P (prime or factor of 42) write your answer as a percentage

Answer 1

Assuming each number has an equal chance of being landed on, we know that 6 and 7 are factors of 42, so that's 2/4 possible numbers. 7 is also prime, so that is included in the 2/4 numbers that are factors of 42. This means that P(Prime or Factor of 42) = 2/4 = 1/2.

Hope this helps! Mark M's explanation goes into more depth with the actual formula you use.

Answer 2

6 is a factor of 42 but is not prime

7 is a factor of 42 and is prime

8 and 9 are not factors of 42 and are not prime

So, if the only numbers on the spinner are 6, 7, 8, 9, then

P(prime or factor of 42) = P(prime) + P(factor of 42) - P(prime and a factor of 42)

= 1/4 + 2/4 - 1/4 = 1/2