# Thread: 11+ Maths question -

1. ## 11+ Maths question -

I do not know how to show working out mathematically for the question below to my 11 year old daughter.

In my greenhouse, a tomaoto plant anda sunflower plant are grown by side by side. On ath 24th June , the tomato plant is 16 cm tall whereas the sunflower is onlty 7 cms tall. The tomaoto plant grows at a constant rate of 1 cm per day and the sunflower plaqnt grows at a constant rate of 1.5 cm per day. On what day will the two plants have the same height?

Thanks

Dee

2. This is pretty simple to do.

To start off call the number of days x, we can then formulate the following equation:

$\displaystyle 16 + x$ and $\displaystyle 7 + 1.5x$.

As we want the day where these two are equal to each other, we place the two equations equal to each other:

$\displaystyle 16 + x = 7 + 1.5x$.

This rearranges to give us

$\displaystyle x = 18$.

Therefore after 18 days the plants will be the same height, on the 12th of July.

Hope this helps, just post back if there is anything you do not understand

Craig

3. You make it look so easy. Thank you very much indeed.

Deee

4. No problem

The hard thing about these questions is finding the formulas hidden in the wording, once you have got the hang of deciphering rediculous questions involving sunflowers, the maths involved is nothing.

Feel free to thank me

5. Originally Posted by craig
Feel free to thank me
If she won't I will. Some people need more awareness of the button...

You deserve the click