Well, i have the answer to your question:
dealership A : 500 cash back , 5% tax
Becky : 15,000 + 0.05(15000) - 500 = 15,000 + 750 - 500 = 15,250
Michele : 20,000 + 0.05(20,000) - 500 = 20,000 + 1000 - 500 = 20500
dealership B : 1000 cash back, 8% tax
Becky : 15,000 + 0.08(15,000) - 1000 = 15000 + 1200 - 1000 = 15,200
Michele : 20,000 + 0.08(20,000) - 1000 = 20,000 + 1600 - 1000 = 20600
1. Becky will get the better deal at dealership B.....she saves 50 bucks
2. Michele will get the better deal at dealership A...she saves 100 bucks
1 cup = 0.25 quarts,
12+15+5 = 32 cups:
32 * .25 = 8 quarts
Since there is no repetition allowed, there are 10 possibilities for the 1st digit, 9 for the 2nd, 8 for the 3rd, and 7 for the 4th. This gives a total of (10)(9)(8)(7) = 5040 four-digit codes.
For all odd digits to be used, there are 5 possibilities for the 1st digit (1,3,5,7,9), 4 for the 2nd, 3 for the 3rd, 2 for the 4th. This gives a total of (5)(4)(3)(2) = 120 codes that only use odd digits.
Therefore there are 5040 - 120 = 4920 codes that do not consist of all odd digits. The probability is 4920/5040 = 41/42.