1. The problem states that Frank started with 100 units of money. 2. He spent \frac{1}{5} of his money on transportation. Calculate this amount: $$100 \times \frac{1}{5} = 20$$ 3. He also spent \frac{3}{10} of his money on lunch. Calculate this amount: $$100 \times \frac{3}{10} = 30$$ 4. To find the total amount spent by Wednesday, add the two amounts: $$20 + 30 = 50$$ 5. Therefore, Frank spent 50 units of money by Wednesday. The correct answer is b. 50.