20 points!   suppose you find six articles related to the topic of your research paper. in how many ways can you choose four articles to read a.720 b.30 c.360 d.15

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

Acompany manufactures large valves, packed in boxes. a shipment consists of 1500 valves packed in 75 boxes. each box has the outer dimensions 1.2 x 0.8 x 1.6 m and the inner dimensions 1.19 x 0.79 x 1.59 m. the boxes are loaded on a vehicle (truck + trailer). the available capacity in the vehicle combination is 140 m3. each valve has a volume of 0.06 m3. - calculate the load factor on the box level (%). - calculate the load factor on the vehicle level (%). - calculate the overall load factor (%).

Which number completes the inequality? 2/3 < _ < 7/9