If a, b, and c are positive numbers such that (a/(a+b))(10) + (b/(a+b))(20)=c and if a<b which of the following could be the value of c?
Choose the correct choice from the following
A) 10
B) 12
C) 15
D) 18
E) 30
The answer is D. For any positive a and b, c is a number between 10 and 20. Since a &lt; b, weight of 10 is inferior of weight of 20 -&gt; c is &gt; 15 -&gt; 18 is the answer.
<result>D</result>
If a, b, and c are positive numbers such that (a/(a+b))(10) + (b/(a+b))(20)=c and if a<b which of the following could be the value of c?