1) Little Jimmy forgot to bring his calculator to school. How can he solve the following problem using only his own brain power?
672 - 332
512 - 492
512 - 492
2) If you reverse the digits in Debby's age, you obtain her grandfather's age. As it happens, his birthday is tomorrow, when his age will become twice Debby's.
Find both their ages.
3) Robin has math test grades of 85, 79, 91, and 88. His teacher has told the class that any student averaging under 87 for the year will have to go to summer school. What grade does Robin have to get on the final exam (last test!) to avoid going to summer school?
4) Out of 100 people surveyed, 20 hadn't touched any reptile, 67 had touched a snake, and 71 had touched a lizard. How many of those surveyed have touched both a snake and a lizard?
5) You wake up in a pitch-black room in a hunting lodge, and there's no light handy. In your duffel bag there are six black socks and six white ones. You want to pick out a matching pair. What is the smallest number of socks you can take out of the bag to be sure of getting a pair of the same color?
6) A farmer has both pigs and chickens. Together, the pigs and chickens have 136 heads and 402 legs. None of the pigs or chickens are mutant or injured! How many pigs does she have? How many chickens?
7) "I saw your boy last night," said Charlie. "Hadn't seen him in years. How old is he now?"
Tom smiled. "Ken's not as old as he makes out to be," he replied. "Seven years ago he was a third my age, and seven years from now, I'll be twice his age."
That told Charlie all he needed to know.
So how hold is Tom, and how old is his son Ken?