It would take 70,000 seeds if five out of seven are good. So over a quantity of 50,000 plants desired, you would sow 70,000 seeds. As 20,000 would statistically fail.
Answer:
One 50$, one 5$, and four 1$ bills
150g/12cakes
150/12 = 12.5
12.5g/cake
12.5x30 = 375
Therefore, you need 375g for 30 cakes.