It takes a night security officer 20 mins to check each of the doors in an office building to make sure they are locked. what is the officers rate of work ?

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?

Which is the best estimate of the product of 0.9 x 0.88? 0 0.25 0.5 1

How to find the volume of an area and height