The length of a rectangular field is 7/5 its width. If the perimeter of the field is 336 meters, what is the width of the field?  Select the correct option:
A) 50
B) 60
C) 70
D) 80
E) 90

Rationale: "let l be the length and w be the width . l = ( 7 / 5 ) w perimeter : 2 l + 2 w = 336 , 2 ( 7 / 5 ) w + 2 w = 336 solve the above equation to find : w = 70 m and l = 98 m . correct answer c ) 70"
Answer: C