Plz men ..help me to solve this question I'm hopping for detailed solution

Plz men ..help me to solve this question I'm hopping for detailed solution A sonometer wire is in unison with a tuning fork. when it is stretched by certain weight in air, corresponding resonating length is 100 cm. If weight is completely immersed in water, the resonating length of wire decreases to 90 cm. Find the density of rnaterial of weight. (density of water = I g/cc)