John and sam have a lawn mowing service. At one home. john can mow the lawn by himself in 2 hours, but it takes sam 2.5 hours. How many hours t will it take them to mow the same lawn together

Ineed to know the answer to this algebra question.

The weight v of an object on venus varies directly with its weight e on earth. a person weighing 120 lb on earth would weigh 106 lb on venus. how much would a person weighing 150 lb on earth weigh on venus?

Anew landowner is interested in constructing a fence around the perimeter of her property. her property is 1,080√30 feet wide and 500√20 feet long. what is the perimeter of the property? (recall that the perimeter is the sum of each side of a shape or boundary). a 1,580√40 feet b. 5,320√5 feet c. 3,160√20 feet d. 10,640√5 feet