11 Plus Exams Forum

Any suggestions?

Question.

48, 24, 72, 18, 90

Answer is 15

Does anybody know what the sequence is?

Flosi

It looks to me as alternatively dividing and multiplying by increasing one number each time:

48 / 2 = 24
24 x 3 = 72
72 / 4 = 18
18 x 5 = 90
90 / 6 = 15

Hi Flosi

The sequence alternates between multiplication and division, whilst moving up one number each time:

48 /2=24
24 x3=72
72 /4=18
18 x5=90

So: 90 /6=15

It's quite refreshing for me to be answering rather than the one asking question!

Regards, UmSusu

Kiwimum beat me to it! I need to learn to type quicker

Wow

Thanks guys for a quick response.

Wish I could think that quick!

Flosi

What levels are these qus? Are they 11+ standard? They seem very challenging to me!

Yes they are 11 plus standard.

Patricia

Thank you, Patricia.

Roughly how long would they be expected to spend on a question like this? That's quite a lot of mental maths trial and error to see which pattern emerges, isn't it?

With practice, and making notes, these questions should be completed within 30 seconds.

I weekly give daily exercises to include doubling/halving/multiplying/division/adding/subtraction a little every day, 10 sums at the breakfast table will give surprising results over a short period of time.

Divide an A4 sheet into 6 sections in each section place 10 sums, each section containing the same type of problem, all adding, all subtraction, all doubling/halving etc etc. Do not use huge numbers, once the smaller numbers have been mastered the larger numbers become easy.

One section a day is not too much on the work load.

Patricia

Patricia, you are brilliant. Thank you so much. Your support is priceless.

When I set these daily sums, do you advise straight multiplying, for example, or a multiple +1, so they get into the habit of looking for the hidden extras?