Three numbers are in the ratio 3:5:7. The largest number is 28. What is the difference between smallest and largest number?
Answers:
A) 12
B) 14
C) 16
D) 18
E) 20
The three numbers are 3x, 5x, and 7x.   The largest number is 28 = 7*4, so x = 4.   The smallest number is   3*4= 
<gadget id="calculator">  3*4</gadget>
<output>12</output>
12.   28 - 12= 
<gadget id="calculator">28 - 12</gadget>
<output>16</output>
16   The answer is 16.
<result>C</result>
Three numbers are in the ratio 3:5:7. The largest number is 28. What is the difference between smallest and largest number?