What is the length of the longest pole which can be kept in a room 12 m long, 4 m broad and 2 m high?  Choose the correct option.
A) 7	B) 12.8	C) 11	D) 13	E) None
Explanation:   d2 = 122 + 42 + 22 = 12.8   12.8)
<result>B</result>
What is the length of the longest pole which can be kept in a room 12 m long, 4 m broad and 2 m high?