While using kinematic devices or mechanisms, certain applications may not be represented by a single task. This scenario calls for hybrid task synthesis where the entire motion cycle becomes active, i.e., during a single crank rotation the same mechanism performs different subtasks. The objective of the present work is to introduce a design process of adjustable offset slider-crank mechanism for function generation along with path generation with prescribed timing simultaneously. The lengths of the input link and offset link are made adjustable. The mechanism comprises the original offset slider crank mechanism along with a ternary link, a roller link and a guiding slot in the fixed link for each of the variable-length links. While the coupler point traces a desired path with prescribed timing (i.e. coordinated with the input link rotation), the slider displacement generates the desired input-output functional relation. The desired function and path are generated simultaneously in the same range of input motion. An n-degree polynomial is used to design the contours of the guiding slots, n being the number of precision points. A case study is provided to verify the feasibility of this new synthesis method.