Question

Some boats have motors and go further into the sea. Since they go far out they can catch more fish. These boats travel faster, at the speed of about 20 km in one hour.
• How far would the motor boats go in three and a half hours?
• How much time will they take to go 85 km?

Answer 1

• Distance covered by boat in 1 hour = 20 km

Distance covered by boat in $\frac{1}{2}$ hour = 10 km
Distance covered by boat in $3\frac{1}{2}$ hours = 20 km + 20 km + 20 km + 10 km

So, the boat can cover 70 km in $3\frac{1}{2}$ hours.

• Total distance to be travelled by boat = 20 km + 20 km + 20 km + 20 km + 5 km

Distance covered by boat in $\frac{1}{4}$ hours = 5 km
Time taken to travel 85 km = 1 h + 1 h + 1 h + 1 h + $\frac{1}{4}$ h
= $4\frac{1}{4}$ h

They will take $4\frac{1}{4}$ h to go 85 km.