In a drawer there is a number of pair of socks, out of which 1/5 are white pairs, 1/10 are black pairs, and the remaining 7 pairs are red. How many white socks are in the drawer?
Choose the correct choice from the following answers
A) 10  B) 2  C) 1  D) 7  E) 4
Let x be the total number of pairs of socks.   x(1/5+1/10)=3x/10 the number of pairs white and black.   x-3x/10=7x/10 is the number of red pairs of socks   7x/10=7 implies x=10.   There are 10 pairs of socks out of which 1/5 are white, that is, 1/5*10=2.   Thus, the total number of white socks is 2*2= 
<gadget id="calculator">2*2</gadget>
<output>4</output>
4.   Answer 4 4.
<result>E</result>
In a drawer there is a number of pair of socks, out of which 1/5 are white pairs, 1/10 are black pairs, and the remaining 7 pairs are red. How many white socks are in the drawer?