Which of these is equivalent to the expression s+s + s + s + 12 ?

Samantha swam upstream for some distance in one hour. she then swam downstream the same river for the same distance in only 12 minutes. if the river flows at 4 mph, how fast can samantha swim in still water?

Which of the following is the sum of 3 1/6 + 6 3/8?

Find the center of the circle that can be circumscribed about efg with e(4,4) f(4,2) g(8,2)