1. Department of Mathematics, Faculty of Physical Sciences, Ahmadu Bello University, 810211 Zaria, Nigeria
2. Department of Mathematics, College of Science, Taif University, P.O. Box 1109, Taif 21944, Saudi Arabia
3. Department of Mathematics, College of Science and Arts at Khulis, University of Jeddah, Jeddah 23218, Saudi Arabia
4. College of Business at Khulis, University of Jeddah, Jeddah 23218, Saudi Arabia