For an experiment in which g is calculated from g=2s/t2, the percentage error in g (%Δg) in terms of the percentage errors in measuring the fall distance s (%Δs) and the fall time t (%Δt) is
a) %Δg=2%Δs+%Δt
b) %Δg=%Δs−2%Δt
c) %Δg=%Δs+2%Δt
d) %Δg=2(%Δs+%Δt)