3. Biologists captured 400 tigers, tagged them, and released them back into the same area. Two months later they caught 100 tigers, 30 of which were tagged. Estimate the number of tigers in the area.

Jack has a piece of red ribbon that is two times as long as his piece of blue ribbon. he says that he can use two different equation to find out how long his piece of red ribbon is compared to his piece of blue ribbon is. is he correct? explain his reasoning

Solve the following inequalities and show the solution on a number line. 3/4 (2x-7) ≤ 5

In a two-digit number the units' digit is 7 more than the tens' digit. the number with digits reversed is three times as large as the sum of the original number and the two digits. find the number.