A certain toy store's revenue in November was 1/5 of its revenue in December and its revenue in January was 3/4 of its revenue in November, then the store's revenue in December was how many times the average (arithmetic mean) of its revenues in November and January?  Choose the correct choice from the following answers
A) 1/4	B) 1/2	C) 2/3	D) 2	E) 6
Let Dec rev =100   Then Nov rev is 1/5 (100) =&gt; 20   Therefore Jan rev = 3/4(Nov rev) = 3/4(20) =&gt; 15   Hence Dec rev = x*( Nov rev+Jan rev)/2   100 = x* (20+15)/2   x = 100/17.5 =&gt; 5.71=6   Ans) 6
<result>E</result>
A certain toy store's revenue in November was 1/5 of its revenue in December and its revenue in January was 3/4 of its revenue in November, then the store's revenue in December was how many times the average (arithmetic mean) of its revenues in November and January?