You have diving lessons every fifth day and swimming lessons every third day. today you have both lessons. in how many days will you have both lessons on the same day again?

7x+8y=-18, 4x-9y=-3 solve the system of equations

Ben is three times as old as samantha, who is two years older than half of michel's age. if michel is 12. how old is ben?

The random variable x represents the number of phone calls an author receives in a day, and it has a poisson distribution with a mean of 8.7 calls. what are the possible values of x