SOLUTION: rikkies locker number is a two digit number the number is less than 70 and is an even multiple of 10 what three number
2 answers:
You might be interested in
Answer:
Step-by-step explanation:
This book has 500 pages in total.
We should split up the place values.
1 - 9
One only appears once.
1
10 - 19
One appears 11 times.
1 + 11
20 - 99
One only appears 8 times.
1 + 11 + 8
Add:
1 + 11 + 8
=> 20
Since the same is for 200-299, and so on. Let us add twenty four times.
20 * 4
=> 80
Looking back to 100-199, there are 120 ones.
Add:
120 + 80
=> 200