5 a) How many even numbers can be formed from the digits 1, 2, 3, 4, 5?

b) How many of these numbers are greater than 3000?

3 answers

You have conflicting restrictions, so take it in cases
To be greater than 3000, the number must start with either 4 or 5

case1 : it start with a 4, that means you have 1 choice to make it even, namely the 2
number of ways = 1*3*2*1*1 = 6
case2 : it starts with a 5, so you have 2 choices for the unit digit
number of ways = 1*3*2*1*2 = 12

So you have 18 such numbers
can someone answer part a
A motorcycle licence plate consists of two or three letters followed by four digits. How many licence plates can be made?