A straight road connects Town P to Town Q.

At 0900, John left Town P and drove towards Town Q while Gwen left Town Q and drove towards Town P.

At 1200, both John and Gwen passed each other.

At 1400, John reached Town P but Gwen was still 150 km from Town Q.

(a) What is the distance between both towns?

(b) What was the combined speed of both John and Gwen as they approached each other?

Notes to student:

1. If the question above has parts, (e.g. (a) and (b)), given that the answer for part (a) is 10 and the answer for part (b) is 12, give your answer as:10,12