In a group of ducks and cows, the total number of legs are 30 more than twice the number of heads. Find the total number of cows. Pick one:	A) 12	B) 15	C) 16	D) 18	E) 20
Let the number of ducks be d   and number of cows be c   Then, total number of legs = 2d + 4c = 2(d + 2c)   total number of heads = c + d   Given that total number of legs are 28 more than twice the number of heads   =&gt; 2(d + 2c) = 30 + 2(c + d)   =&gt; d + 2c = 15 + c + d   =&gt; 2c = 15 + c   =&gt; c = 15   i.e., total number of cows = 15   Answer is 15.
<result>B</result>
In a group of ducks and cows, the total number of legs are 30 more than twice the number of heads. Find the total number of cows.