What is the product of (-0.9)(-2.4)?

If the measure of xyz is 81 what is the measure of yz

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

If a flying disk is 139 meters in the air and travels at an average of 13 m/s how long is it in the air