A ship 77 km from the shore, springs a leak which admits to 9/4 tonnes of water in 11/2 minutes. 92 tonnes of water would sink it. But the pumps can throw out 12 tonnes of water per hour. Find the average rate of sailing so that the ship may just reach the shore as it begins to sink.	Choose the most appropriate option:
A) 10.5 B) 11 C) 12 D) 13 E) 15
Leak admits 9/4 tonnes water in 11/2 min   =11/2 * 4/9 = 22/9   leak admits 9/22 tonne of water in 5 min   in 1 min in thrws 1/5 tonne of water = 9/22 - 1/5 = 23/110   92/23/11 min = 440 min   22/3 min=7/22/22/3 =&gt; 10.5 km/hr   10.5NSWER 10.5
<result>A</result>
A ship 77 km from the shore, springs a leak which admits to 9/4 tonnes of water in 11/2 minutes. 92 tonnes of water would sink it. But the pumps can throw out 12 tonnes of water per hour. Find the average rate of sailing so that the ship may just reach the shore as it begins to sink.