Just thought I'd remark that by stating the aeroplane is in a "straight, steady, wings level climb", the question presents all the information one needs to make the assumption that lift does in fact equal weight. The straight and level stuff indicates that the aircraft is being subjected to no acceleration forces. If lift were greater than weight, it would accelerate upwards, i.e. would climb at an ever-increasing rate.
Good luck tomorrow, Grass strip basher!