for sonometer wire

l = λ/2

or 2l = v/n                                    here n represents frequency

or n = v/2l

for first wire of 1 m length n= v/2

for second wire of 1.05 m length n=v/2.1

let frequency of tuning fork = n₁

so according to the given condition v/2 = n₁+ 5

and v/2.1 = n₁ - 5

solve now