Table Height
A table has blocks of wood placed on and next to it. Can you work out how tall it is?
Age
14 to 16
Challenge level
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Four identical blocks of wood are placed touching a table in the positions shown.
How high is the table?
If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.
Answer: 90 cm
Label the blocks
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$l$ and $w$ are on different sides of the equations so add to make them cancel: $$\begin{align}&\qquad 84+l=h+w\ \ \\
&\underline{+\quad 96+w=h+l\ \ }\\
&180 + l+w=2h+l+w\end{align}$$ so $2h=180$ and $h=90$