Question 1115801
Plan A: 30x
Plan B: 1400 + 15(x-35)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 
30x < 1400 + 15x - 525
15x < 875
x = 58.33 NOTE: you can't split a person, so at 58 guests and under, Plan A is cheaper. At 59 guests and up, plan B is cheaper.