During a training exercise, a submarine travels 16 km/h on the surface of the water and 10 km/h underwater. If the submarine travelled a distance of 160 km in 12.5 hours, how
long was it underwater?

Which of the following represents a number squared is equal to twenty more than nine times that number ? a) x squared = 9x + 20 b) x squared = 20x + 9 c) x squared > 9 + 20x d) x squared = 9 + x + 20

The larger of two number is 4 less than twice the smaller number. the sum is 41. find the numbers

Write an equation of the line that passes through the point (2, 3) and is perpendicular to the line x = -1. a) y = 1 b) y = 3 c) y = 0 eliminate d) y = -3