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I am quite clever at Maths this but this is really bugging me, I saw this on another forum

Make 69 using the following numbers: 7 8 8 9 9

You can only use each number once and can only add, subtract, multiply and divide

Good Luck all I am gazzumped

9 x 8 = 71
9 - 7 = 2
subtract the 2
=69

9*8 thought was 72

Original Poster

You need to use every number, I should have put that in at the start. Sorry

Lockstockdude;4163872

9 x 8 = 719 - 7 = 2subtract the 2=69

9x8 is 72....71 is prime

John

haha figured afterwards school boy error

pretty sure 9 x 8 is 72.............................

Original Poster

I can get to 68 and 70 but I feel it is impossible but hey I may be proven wrong. Been trying to do it since yesterday just cannot get it out my head, am funny with that sort of thing

I can get 69.875 lol

Is it cheating to do 78 - 8 - (9/9) = 69?
Do I have to use each digit as an individual number?

Why did it have to be 69?

9x8=72
square root 9=3
72-3=69
8 - 7 = 1, 69 x 1 = 69

Old Bear;4164083

Is it cheating to do 78 - 8 - (9/9) = 69? Do I have to use each digit as … Is it cheating to do 78 - 8 - (9/9) = 69? Do I have to use each digit as an individual number?

Yes that's cheating lol, what would Vorderman say!

Original Poster

I haven't got a clue why it is 69 and like I said you can ony use each number once and all numbers have to be used. You can ADD, SUBTRACT, MULTIPLY & DIVIDE. Just think of countdown lol

Such as

68 is 8 X 9 = 72, 7 - 9 = 2 / 8 = 4, 72 - 4 = 68
70 is 8 X 9 = 72, 9 - 7 = 2, 72 - 2 = 70

andymack;4163902

pretty sure 9 x 8 is 72.............................

haha... pretty sure 9 x 8 is 71 :thumbsup:

Banned

strike;4164124

9x8=72square root 9=372-9=698 - 7 = 1, 69 x 1 = 69

Thought that myself but would it count since

You can only use each number once and can only add, subtract, multiply and divide

I tihnk someone's having you on mate.

Original Poster

I agree but I thought I would try on here to see if there was any unknown mathematic genius that could solve it, I will keep trying though unless it is proven impossible cause it is really ticking me off now

7+8+8 = 23

Turn one 9 upside down to make it a 6

9-6 = 3

Multiply the totals of the above two sums 23 x 3 = 69

NV