What is the sum (arithmetic series) 4+7+10+13+.. to 50 terms?

Offering 30 if a plus b plus c equals 68 and ab plus bc plus ca equals 1121, where a, b, and c are all prime numbers, find the value of abc. the answer is 1978 but i need an explanation on how to get that.

Aladder that is 20 ft. long against the side of a building. f the angle formed between the ladder and the ground is 75 degrees, how far is the bottom of the ladder from the base of the building?

(: the two box-and- whisker plots below show the scores on a math exam for two classes. what 2 things do the interquartile range tell you about the two classes?