Abstract
The present article is concerned with deriving necessary conditions for the existence theory of solution to a class of delay Fredholm-Volterra integro-differential equations using fixed point approach. Also via the use of the Haar collocation method, a numerical scheme is established. With the help of the mentioned method the considered problem is transformed into a system of algebraic equations which is then solved for the required results by using Gauss elimination algorithm. Further the necessary conditions required for a numerical technique to be held like maximum absolute errors, efficacy and comparison with exact solution as well as with the results of other numerical schemes are performed by taking various numbers of collocation points. The obtained results are compared with the results of the Spline functions algorithm for the concerned problems. Various pertinent test problems are given to testify the results.