### Bat Wings

Two students collected some data on the wingspan of bats, but each lost a measurement. Can you find the missing information?

### Kate's Date

When Kate ate a giant date, the average weight of the dates decreased. What was the weight of the date that Kate ate?

### Balancing the Books

How many visitors does a tourist attraction need next week in order to break even?

# The Average Age

##### Age 11 to 14 Short Challenge Level:

The sum of the ages of 5 teachers is 190, so the mean age is 190$\div$5 = 38.

The mean age of the teachers is 10 years greater than the median age, so the median age must be 10 less than 38, so the median age is 28 - so the ordered list of the ages is __, __, 28, __, __.

The modal age is 5 years less than the median age, so the modal age is 23.

There must be at least 2 teachers who are 23. The third youngest teacher has the median age, so the youngest three teachers are 23, 23, 28.

Of the two older teachers, one is 56. So four of the teachers are 23, 23, 28 and 56. Subtracting these from 190 will give the age of the remaining teacher.

23 + 23 + 28 + 56 = 130

So the other teacher must be 60, since 130 + 60 = 190.
You can find more short problems, arranged by curriculum topic, in our short problems collection.