A fraternity charged $2.00 admission for dudes and $1.00 for ladies for their finals week bash. The fraternity made $100.00 and sold 70 tickets. How many ladies attended the party?

Given : 2D + 1L = 100,
And D + L = 70

This is a simultaneous equation can be solved as follows

2D + L = 100
- D - L = -70
————————————-
D - 0 = 30

i.e D (number of dudes) = 30

Therefore, since we already know the fraternity sold 70 tickets in total,

70 -30 = 40 (the number of ladies attended)