Two rulers are the same length. Ruler A is divided into 357 units while ruler B is divided into 255 units The rulers are placed side by side with the 0 marks lined up and the 375th mark of ruler A aligned with the 255th mark of ruler B. How many total places will the marks on the rulers be aligned?

Answer 1

357A = 255B
A/B = 255/357 = 5/7

A - B
5 7
10 14
15 21
...
255 357

there will be 52 of those line-ups , obtained by 255/5 = 51, or 357/6 = 51, plus the line-up at the zeros

Answer 2

A ruler measures length to the nearest 0.25 inches. Which is the most appropriate way to report length using this ruler?