Your doctor gives you three pills and tells you to take one every half hour. How much time will have passed by the time you’ve taken all three pills?

Suppose a small bank has one teller and customer transactions take 10 minutes on average. With 5.8 customers arriving per hour, what is the expected wait time? What would it be if you added a second teller?

When the day before yesterday was referred to as the day after tomorrow, the day that was then called yesterday was as far away from the day we now call tomorrow as yesterday is from the day which we shall now be able to speak of last Monday as a week ago yesterday. What day is it?

How much does a bottle of wine weigh if it is 1 kilogram plus half its own weight?

What number is twice the sum of it’s digits?

Maya’s mother asked her to buy some stamps. The available stamps were 3 cents, 9 cents, 11 cents, 17 cents and 21 cents. Her mother asked her to buy eight each of three stamps and nine of each of the remaining two stamps. Unfortunately, Maya forgot which stamps she was supposed to buy eight and nine of. Luckily, her mother had given her $5, the exact amount required to buy the stamps. Which stamps did she buy?