This is a round robin style tournament. Given that there are 25 people, and order doesn't matter meaning that the combination AB is equivalent to BA you must use the choose formula.
Thus the answer should be 25C2 or <em>25! / [(25-2)! * 2!] = 300</em>
Rachel spends 6 hours 45 minutes a week trying to learn to play the violin.
Step-by-step explanation:
Step 1; Rachel learns for 45 minutes a day from Monday through Friday and in the weekend she learns to play the violin for one and a half hours. So she learns for the following periods of time
Monday - 45 minutes
Tuesday - 45 minutes
Wednesday - 45 minutes
Thursday - 45 minutes
Friday - 45 minutes
Saturday - 90 minutes (60 × 1.5 hours)
Sunday - 90 minutes (60 × 1.5 hours)
Step 2; To determine how much time she practices in a week we just add the individual times she plays on each day.
Total time practices in a week = 45 + 45 + 45 + 45 + 45 + 90 + 90 = 405 minutes = 6 hours 45 minutes.
