Let's try to answer the following questions
1）"Mother, I wish you would give me a bicycle", said a girl of twelve the other day.
"I do not think you are old enough yet, my dear", was the reply.
"When I am only three times as old as you are you shall have one."
Now, the mother's age is forty-five years. When may the young lady expect to receive her present?
2）1 2 3 4 5 6 7 8 9 = 100
It is required to replace arithmetical signs between the nine figures so that they shall equal.