1)A palindrome is a positive integer that is the same when reading forwards or backward. For example, 7 is a palindrome, as are 121 and 7739377. Determine the number of palindromes with 7 digits.

2)How many 4-digit numbers have the second digit even and the fourth digit at least twice the second digit?

3)There are 16 competitors in the Alcumulus Trainer competition, including 3 from Oslo. The gold medal goes to first place, silver to second, and bronze to third. Suppose that the judges that exactly one student from Oslo must win a medal (no more and no less). Now, how many ways are there to award the medals?

FBIOPENUP Apr 28, 2020