If 0 < a < b and k = (5a + 5b)/b , which of the following must be true? Choose the correct choice from the following answers:
A) k < 2 B) k < 7 C) k < 9 D) k > 9 E) k > 11
Please follow posting guidelines (link in my signature) especially writing the correct topic title. Also do mention the source of the question if you select the tag:Source-Other Please Specify.   As for your question, it is very simple and straightforward with number plug in.   Assume a=1 and b=2 as a &lt; b, you get k = (5+10)/2 = 7.5. This eliminates all but option k &lt; 9 , making it the correct answer.
<result>C</result>
If 0 < a < b and k = (5a + 5b)/b , which of the following must be true?