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 43. 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 + 43   6x = 43 =&gt; third number is 43.   Answer: Option 43
<result>D</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 43. Find the third number?