please use the same tables so that I can understand what is going on

Consider the following reference string: a._How many page faults would this string produce under the FIFO page replacement strategy with three frames? b._How many page faults would this string produce under the OPT replacement strategy with three frames? 4 221435 2 4 5 214 31 How many page faults would this string produce under the LRU replacement strategy with three frames? c