Andrea runs 4 miles every day, but she wants to increase her distance in order to run a 26 mile marathon. She decides to add 2 miles each day to her distance until she achieves her goal. If she starts with 6 miles today, how many miles will she have run in total, by the time she achieves her 26 mile goal? The correct answer is 176 miles.

By the time she achieves her 26 mile goal Andrea will have run 176 miles.

Step-by-step explanation:

Since Andrea runs 4 miles every day, but she wants to increase her distance in order to run a 26 mile marathon and she decides to add 2 miles each day to her distance until she achieves her goal, to determine, if she starts with 6 miles today, how many miles will she have run in total, by the time she achieves her 26 mile goal the following calculation should be performed:

6 + 8 + 10 + 12 + 14 + 16 + 18 + 20 + 22 + 24 + 26 = X

14 + 22 + 30 + 38 + 46 + 26 = X

36 + 68 + 72 = X

36 + 140 = X

176 = X

So, by the time she achieves her 26 mile goal Andrea will have run 176 miles.