Help please Research

Jonathan can type 20 documents in 40 minutes ,and susan can type it in 30 minutes and jack can type it in 24 minutes working together ,how much time will it is take them type the same document

Mrs.sling bought a pound of green beans for $1.80. how much will mrs.tennison pay for 3 1/2 pounds of green beans?

Round each of the decimals to the nearest hundredth a. 0.596 b. 4.245 c. 53.6843 d. 17.999