please help solve A-C

1. You go to the library to study for the OM exam. You will do as many problems as you can in 4 hours of studying, taking no breaks and having no interruptions. You timed the first problem you did and found it took 20 minutes. You decide that there is a 90% learning rate here that will continue with the remaining problems. Assume that if there were no learning effect, each problem would take the same amount of time. a. (15 points) How much time will it take to do the third problem? b. (15 points) Approximately how many problems will you be able to complete in the 4 hours? Assume the learning effect will continue, and you take no breaks. You must show your work for full credit. c. (15 points) At the conclusion of the 4 hour study session, you see a friend that has also been studying for the exam. Your friend has completed 35 problems in the same 4 hours, with the first problem taking 20 minutes. What was your friend's approximate learning percentage? You must show your work for full credit