Adeer and bear stumble across a sleeping skunk. they run away from it in opposite directions- the deer at a speed of 8 feet per second and the bear at a speed of 5 feet per second. how long will it be until the pets are 156 yards apart?

The total distance between them is 156.  If the deer runs d feet, then the bear runs 156-d.  The rate for the deer is 8, the rate for the bear is 5.  The time for both is the same, the deer just gets farther because he runs faster. If the time is the same for both, solve for t and set the ratios equal to one another.  If d=rt, then t=d/r.  The ratios would then look like this: .  Cross multiply to get 5d=1248-8d and 13d=1248. Solve for d to get d=96.  Now sub that distance into one of the original equations, d=8t is one of them, to get that the time, t, is 12 seconds.