As shown by figure 1 springs can be used in series and parallel (with an analogy with resistors and capacitors)
Formulas
a) Springs in series
Stot = s1 + s2 + s3 + ......+ sn (f2.41a)
Ftot = F1 = F2 = F3 = ..... = Fn (f2.41.b)
Rtot = R1 + R2 + R3 + ..... + Rn (f2.41.c)
Where: Stot, s1, s2, s3, sn are the deformations
Ftot, F1, F2, F3, Fn are the involved forces
Rtot, R1, R2, R3, Rn are the spring rates
b) Springs in parallel
Stot = S1 = S2 = S3 = ...... = Sn (f2.42a)
Ftot = F1 + F2 + F3 + .... + Fn (f2.42b)
1/Rtot = 1/R1 + 1/R2 + 1/R3 + ..... + 1/Rn (f2.42.c)