A mathematical question for you

[motoukenin]

equation is (s-9)/10 + 9x10^x = 4s

transpose to (39s+9)/90 is a power of 10

powers of 10 are 10, 100, 1000, 10000, 100000 ...etc

if s is an integer then first to solve is 100000

therefore (39s+9)/90 =100000

s = 230769

Think that's how a 10 year old is supposed to solve this, of course when he gets to 17 he will know everything anyway and should give the correct answer without any working out.

[BrilloPad]

equation is (s-9)/10 + 9x10^x = 4s

transpose to (39s+9)/90 is a power of 10

powers of 10 are 10, 100, 1000, 10000, 100000 ...etc

if s is an integer then first to solve is 100000

therefore (39s+9)/90 =100000

s = 230769

That is one answer. TRy http://forums.contractoruk.com/gener...ml#post2305476

[motoukenin]

That is one answer. TRy http://forums.contractoruk.com/gener...ml#post2305476

Too complicated an answer, getting something into a power of 10 which all 10 year olds will know is the key here, not sure if the 10 year old that can do the transposition or get to the equation in the first place would be able to deal with life when he/she gets to 18 would be my concern so I would be pretty happy to have a 10 year old that could not solve it, in fact if I do have kids I might just give him/her this equation just to make sure they can't.

[DeadEyedJacks]

Last question on paper

It's worth noting that this was the last question on a paper from King Edwards School, Birmingham in 2011.
11+ specimen papers

I reckon it was either put there to keep candidates busy until the allocated time was up

Or as a one mark "tie-breaker" to ensure not everyone got 100% on this section.

[MancMan]

Thanks very much to all who have helped with this one. Much appreciated. I won't have time until tomorrow to think about your replies and try to follow, but just wanted to say thanks very much.