Solve for x mathematics

Arefrigeration system at your company uses temperature sensors fixed to read celsius (°c) values, but the system operators in your control room understand only the fahrenheit scale. you have been asked to make a fahrenheit (°f) label for the high temperature alarm, which is set to ring whenever the system temperature rises above –10°c. what fahrenheit value should you write on the label

Can someone me with my math problem pls my teacher is on my back about this

One file clerk can file 10 folders per minute. a second file clerk can file 11 folders per minute. how many minutes would the two clerks together take to file 672 folders?