Justine swims freestyle at a pace of 150 laps per hour. Justines freestyle speed is three times faster than her butterfly speed how fast does she swim breaststroke let b represent Justines butterfly speed in laps per hour and r represent justices breaststroke speed in laps per hour

Answer:her breaststroke speed is is 30 laps per hour

Step-by-step explanation:

Let b represent Justine's butterfly speed and

Let r represent Justine's breaststroke speed.

Justine swims freestyle at a pace of 150 laps per hour. Justine swims breaststroke 20 laps per hour slower than she swims butterfly. This means that

r = b - 20

If Justine's freestyle speed is three times faster than her butterfly speed, it means that

3b = 150

b = 150/3 = 50

Substituting b = 50 into r = b - 20, it becomes

r = 50 - 20 = 30