Percentages and Time

Question

Allyson answers 24% of her math problem in 30 minutes. She still has 10 math problems left. How many homework problems has Allyson already completed? Working at the same rate, how many more minutes will it take to finish her math homework?

Answer 1

I must assume that, in your first sentence, you meant HOMEWORK PROBLEMS (plural) when you wrote PROBLEM.

 

So 76% of those problems remain; 10 = 0.76n

 

Therefore n = 13.16, approximately.  This is an unsatisfactory result, because there ought to be an exact integer # of problems.

 

On the other hand, one can easily estimate, since she has done about ¼ of the entire assignment (24%), that it will take 4 times 30 min = 2 hours to wrap up the whole assignment. BUT THAT ASSUMES THAT A UNIFORM RATE OF WORK IS POSSIBLE, and we all know that some problems are easy, and others can seemingly take forever because we don't get the necessary insight.

 

Overall, this is a rotten question, and you can share this opinion with parents and teacher.  (Could it be traceable to Common Core?)