When Grandma was asked about her age she told her grandchildren the following:
-"If the age of the oldest of you will be added to the product of ages of the younger two,- you would get my current age."
The three boys, Alex, Bob and Cid, started their
thinking, but only Bob, the middle child provided
the correct answer and added:
"If we had to perform the above operations a year ago - we would be off by 14 years...
What were the boys' Grandma's ages, given Alex's age was a prime number?
A professor tells his class that he will give them a surprise examination sometime next week.
For our purposes, an examination is considered a "surprise" if on that day, the class is not 100% sure that they will get an examination. (If they only suspect it, the examination can still be a surprise.)
Having given the class this warning, is it still possible for the professor to give them a surprise examination next week? (Assume that he will not give them an exam if it will not be a surprise.)