Peter solved 42 questions in one hour and Jack solved 19 questions in same time. Who solved more questions in one hour and by how much?

Peter solved 42 questions in one hour and Jack solved 19 questions in

1.	Peter solved 42 questions in one hour and Jack solved 19 questions in same time. Who solved more questions in one hour and by how much?
A.	Peter; by 23
B.	Jack; by 13
C.	Peter; by 13
D.	Jack; by 23
E.	None of these
Answer» B. Jack; by 13