Answer:
18.18% of employees rode the bus to work last year
Explanation:
This question can be solved using a rule of three.
Last year, a proportion of x employees riding the bus was 100% = 1.
This year, 20% = 0.2 ride the bus, which is 100 + 10 = 110% = 1.1 of last year.
So
0.2 - 1.1
x - 1
0.1818*100 = 18.18%
18.18% of employees rode the bus to work last year