Abstract Algebra: Theory and Applications · Problem 13.17
Group Actions — Thomas Judson
Mathematics — Abstract Algebra · solvable-groups
Problem
Let N be a normal subgroup of G. If N and G/N are solvable groups, show that G is also a solvable group.
Hint. If N and G/N are solvable, then they have solvable series
N=Nn⊃Nn−1⊃⋯⊃N1⊃N0={e}G/N=Gn/N⊃Gn−1/N⊃⋯G1/N⊃G0/N={N}.