The conversation between human and AI assistant.
How many 4 digit numbers divisible by 4 can be formed from the digits 1, 2, 3, 4, and 5?
That makes sense. Can you explain why the last two digits need to be divisible by 4 for the whole number to be divisible by 4?
Sure! A number is divisible by 4 if the number formed by its last two digits is divisible by 4. For example, in the number 1234, the number formed by the last two digits (34) is not divisible by 4, so the whole number is not divisible by 4. However, in the number 1432, the number formed by the last two digits (32) is divisible by 4, so the whole number is divisible by 4. Therefore, to form a 4 digit number that is divisible by 4, the last two digits of the number must be divisible by 4 as well.