Three numbers are in the ratio 5 : 6 : 7. The sum of its longest and smallest numbers equals the sum of the third number and 84. Find the third number?  Choose one.
A) A)37	B) B)85	C) C)48	D) D)43	E) E)84
Let the numbers be 5x, 6x, 7x.   Largest number = 7x.   Smallest number = 5x.   Third number = 6x.   7x + 5x = 6x + 84   6x = 84 =&gt; third number is 84.   Answer: Option 84
<result>E</result>
Three numbers are in the ratio 5 : 6 : 7. The sum of its longest and smallest numbers equals the sum of the third number and 84. Find the third number?