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.
Umm, That's A lot Of Homework...
the 3 in 350 represents 3 hundred's ( 3 100's ) while the 3 in 403 represents 3 units ( 3 1's )
Step-by-step explanation:
a) determine the rate in km/L
==> 9.5 L/100km = 10.526316 km/L
b) how far can the car travel with 475L petrol
==> 0.210526315789473km/l
c) how many litres of petrol do they need to travel 350 km
==>Liters per km (l/km)2.86×10-3
Liters per 10 km (l/10 km)0.03
Liters per 100 km (l/100km)0.29
Kilometer per liter (km/l)350
