Is there Anyone who Can Solve This?

Question

My daughter is a teacher and the question below was in an dry run for an eleven plus exam, ie, for 10/11 year olds. None of the children managed to get it. I and many others have looked at it for quite a while and just cannot see the next number in the sequence. She wondered if there were some mathematical genuises on SpanishDict and asked me to post this. A simple example is given as a format and you must find the number represented by the question mark.

Example:

1 3 5 7 9 ? Answer 11

Question:

1 8 27 64 ?

• 125 - cogumela Feb 13, 2012
• The answer is 125 because the numbers in the sequence 1,2,3,4,5 are cubed - MarkBaker2 Feb 13, 2012
• And now Cogu and Mark Baker. I even have higher National Certificate, which is above A level, in mathematics. - Eddy Feb 13, 2012
• I wish I came across this question earlier but yes you've got a good answer already :) - mathslover Feb 13, 2012

Answer 1

The sequence is x^3 (or the next integer (whole number) cubed.

E.g.,

1^3=1, 2^3=8, 3^3=27, 4^3=64, 5^3=125, 6^3=216, 7^3=343, etc.

• I cannot believe I didn't see that. It was the only one in about twenty questions that i couldn't get. Well done. - Eddy Feb 13, 2012
• Awesome!!!!!!!!!! - --Mariana-- Feb 13, 2012
• I bow to you my mathematical queen. - Eddy Feb 13, 2012
• Ahh, gee. Gosh. Thanks! ;)) - territurtle Feb 13, 2012

Answer 2

1 8 27 64 92

I added 8 and 1 to get 9....2 and 7 equal 9

I added 2 and 8 to get 10 .....6 and 4 equal 10

I added 3 and 8 to get 11...9 and 2 equal 11

• Sorry Mariana terri already did it, see above. - Eddy Feb 13, 2012