Question
ABC is a right angled triangle in which ∠B=90∘ and BC=a. If n points L1,L2,...,Ln on AB are such that AB is divided in n+1 equal parts and L1M1,L2M2,......LnMn are line segments parallel to BC and M1,M2,...,Mn are on AC then the sum of the lengths of L1M1,L2M2,......LnMn is