A box contains 7 red, 12 green, 17 black and 9 yellow colored balls. If 2 balls are selected without replacement, what is the probability obtains 1 green and 1 is black

Scarlet bought three pairs of sunglasses and two shirts for $81 and paula bought one pair of sunglasses and five shirts for $105 what is the cost of one pair of sunglasses and one shirt?

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?

What expression is equivalent to (84+16)