### Consecutive Numbers

An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.

### Calendar Capers

Choose any three by three square of dates on a calendar page...

### Building Tetrahedra

Can you make a tetrahedron whose faces all have the same perimeter?

# Weighing the Baby

##### Stage: 3 and 4 Short Challenge Level:

Let $m$ be my weight, $b$ be the baby's weight and $n$ be the nurse's weight.

We have
\begin{align} m+b&=78\\ b+n&=69\\ m+n&=137\;. \end{align}
We can add all three equations together like this:
$$(m+b)+(b+n)+(m+n)=78+69+137\;.$$
It follows that $2(m+b+n)=284$ and hence $m+b+n=142$. So the combined weight is $142\;\mathrm{kg}$.

For an extra challenge can you find the weights of each person?

This problem is taken from the UKMT Mathematical Challenges.
View the archive of all weekly problems grouped by curriculum topic