The distance(D km) that sally cycles varies directly as her speed (S km/h). So D=kS. She cycles 16km at an average speed of 8km/h.
a) Find a formula connecting D and S.
Ans= D= 2S (I think this is correct)
b) How far would she cycle at 9km/h?
I need help with this one.
Oh and there's another question I need help with:
The number of dollars (D) is directly proportional to the number of pounds (P) exchanged. Three dollars can be exchanged for 2 pounds.
a) Find a formula for D.
b) How many dollars can be obtained with 12 pounds?
I need help with this question.