Round Robin (RR) scheduling algorithm is the widely used scheduling algorithm in multitasking. It ensures fairness and starvation free execution of processes. Choosing the time quantum in RR algorithm is very crucial as small time slice results in large number of context switches and large time quantum increases the response time. To overcome these problems of RR scheduling, instead of static time slice dynamic time slice can be used to get optimal performance. The objective of this paper is to modify RR algorithm by adjusting time slices of different rounds depending on the remaining CPU bursts of currently running processes and considering their waiting times until that round in respect of the other processes' waiting times. Experimental analysis reveals that the proposed algorithm produces better average turnaround time, average waiting time and fewer number of context switches than existing algorithms.