F.2 Mathematics解釋

John held a''coin drive'' to collect money for a charity.He asked
people to add coins to a straight line of coins to a straight line of coins arranged end-to-end along the footpath.When the line was finished it was 2km long.
John placed his ruler along part of the line and counted exactly twelve coins in 30cm.
About how many coins did John collect?
(A)5000
(B)8000
(C)50000
(D)80000
解釋