Anyone know this?

Study results indicate that the mean length of time people spend on a bus in a city is between 21.2 min and 24.5 min what is the study margin of the error?

Hurry can a triangle can be constructed with angles measuring 115°,55°, and 20°? yes or no

Bob paid $3 less than tim at a local pizza parlor. together they spent $7.80. how much did bob pay for pizza?