What is the value of a 1976 Treasury Department US mint coin collection which consist of a nickel dime bicentennial quarter and Kennedy half dollar?

That doesn't sound right. The set should have a cent and a dollar as well and there should be two coins of each denomination.

If it's a complete set from both mints (Philadelphia and Denver) it might be worth around $10. If it's been broken up the pieces aren't worth much more than face value.