Jumping

After training hard, these two children have improved their results. Can you work out the length or height of their first jumps?
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Jumping


Ben is hoping to enter the long jump at his school sports day.  

One day I saw him manage quite a good jump.

However, after practising several days a week he finds that he can jump half as far again as he did before.

This last jump was $3.75$ metres long.

So how long was the first jump that I saw?

 

 
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Jumping


Now Mia has been practising for the high jump.

I saw that she managed a fairly good jump, but after training hard, she managed to jump half as high again as she did before.

This last jump was $1.20$ metres.

So how high was the first jump that I saw?

 

How did you work these out?

Can you find any other ways of finding a solution?

Which way do you prefer?  Why?