Question

You can kayak around Hamilton island in 3 hours. Kayaking together, you and your friend can kayak around the island in 1.4 hours. Let t be the time (in minutes) your friend would take to kayak around the island alone. Write and solve an equation to find t.

Answer 1

1 / 180 + 1 / t = 1/84

t = 157.5 minutes

Explanation:

3hrs = 180 minutes

1.4 hours = 84 minutes

your rate + friend's rate = rate together

1 lap in 180 min + 1 lap in t min = 1 lap in 84 min

The equation is

1 / 180 + 1 / t = 1/84

subtract 1/180 from both sides

1/t = 1/84 - 1/180

1/t = 0.006349206349

multiply both sides by t

1 = 0.006349206349t

Divide both sides by 0.006349206349

1 / 0.006349206349 = t

157.5 = t

t = 157.5 minutes