What are the missing numbers in the pyramids?
One night two candles, one of which was 3 cm longer than the other
were lit. The longer one was lit at 5.30 pm and the shorter one at
7 pm. At 9.30 pm they were both the same length. The longer one,
burned out at 11.30 pm and the shorter one burned out at 11 pm. How
long was each candle originally?
Consider a watch face which has identical hands and identical marks
for the hours. It is opposite to a mirror. When is the time as read
direct and in the mirror exactly the same between 6 and 7?
Granny has taken up deep-sea fishing! Last week, she caught a fish so big that she had to cut it into three pieces (head, body and tail) in order to weigh it. The tail weighed 9kg and the head weighed the same as the tail plus one third of the body. The body weighed as much as the head and tail together. How much did the whole fish weigh?
If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.
This problem is taken from the UKMT Mathematical Challenges.