There are 5 classes in fifth grade and 6 classes in sixth grade. Each class has 20 students how many are in fifth and sixth grade classes altogether

If sin(x) = 0 and cos(x) = 1, what is tan(x)?

Is the number 128.439 a rational number

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?