Public Transit Usage Percentage

In a city-wide survey conducted by a local government, 250 residents were asked about their transportation modes for commuting to work. The options included driving, biking, carpooling, and public transit. The results showed that:

• 70 residents reported they drive alone to work.
• 50 residents choose to bike as their mode of transportation.
• 80 residents participate in carpooling.
• The remaining residents use public transit.

Based on the survey data, what percentage of respondents use public transit as their commuting method?