The length of time that it takes students to complete the entrance exam for a university is normally distributed with a population mean of µ = 120 minutes and σ = 30 minutes. what is the probability that 1 randomly selected student will take longer than 165 minutes to complete the entrance exam?

Step by step expontion

What is the number for e if you don't knkw then there is no answer you need that number to plug in then multiply that number with 5.9 then add 10

So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.