Let x be the number of gigabyte of data used.
Plan A:
Total cost = 30 + 5x
Plan B:
Total cost = 50 + 2x
Irfan will use between 5 to 8 gb of data per month.
When x = 5
Plan A = 30 + 5(5) = $55
When x = 8,
Plan A = 30 + 5(8) = $70
When x =5,
Plan B = 50 + 2(5) = $60
When x = 8,
Plan B = 50 + 2(8) = $68
He is probably better off using Plan A. Plan A is a cheaper option up to 7gb of data. He should only swap to Plan B if he consistently use 8gb or more data per month.
