Question

A ship develops a leak 12 km from the shore. Despite the leak, the ship is able to move towards the shore at a speed of 8 km/hr. However, the ship can stay afloat only for 20 minutes. If a rescue vessel were to leave from the shore towards the ship, and it takes 4 minutes to evacuate the crew and passengers of the ship, the minimum speed of the rescue vessel in order to be able to successfully rescue the people aboard the ship is (in kmph) ___

Answer 1

As it takes 4 mins to rescue the passengers, in 16 mins the rescue vessel should reach the ship. Now the ship too is traveling towards the shore with 8kmph.

Let the speed of the rescue vessel be X.. Then $X\times \frac{16}{60}+8\times \frac{16}{60}=12$

$\Rightarrow$ X = 37.