Quantitative Aptitude Ques 2335
Question: A boat takes 90 min less to travel 36 miles downstream than to travel the same distance upstream. If the speed of the boat in still water is 10 m/h, the speed of the stream is
Options:
A) 2 m/h
B) 2.5 m/h
C) 3 m/h
D) 4 m/h
Show Answer
Answer:
Correct Answer: A
Solution:
- Let the speed of the stream be x m/h. Then, Speed downstream $ =(10+x),m/h $ Speed upstream $ =(10-x),m/h, $ $ \frac{36}{(10-x)}-\frac{36}{(10+x)}=\frac{90}{60} $ $ 72x\times 60=90,(100-x^{2}) $ $ x^{2}+48x-100=0 $ $ (x+50)(x-2)=0 $ $ x=2,m/h $
BETA
