prep上的一道DS求解释

sophiagregmat

There are two types of rolls on a counter, plain rolls and seeded rolls. What is the total number of rolls on the counter?

(1)The ratio of the number of seeded rolls on the counter to the number of plain rolls on the counter is 1 to 5.

(2)There are 16 more plain rolls than seeded rolls on the counter.
请问plain rolls & seeded rolls 都是神马？
该题的解不会是分别设plain rolls 的总数是x, seeded rolls为y
y/x=1/5
x-y=16这样解出来然后选C吧~~~
谢谢各位解答