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tunesurfer
Dec18-04, 10:16 AM
simple I think not - my son has homework/quiz for fun - try to make numbers from 1 to 50 using the numbers 2,5,1,2 (xmas date)- I think all of them must be used.

for example

25+21=46

(5+1)2-2=34 five plus one squared minus two equals 34

15x2+2=32


weve got some we cant do even usng factorials(dbl/trpl) - decimals and fractions

the ones we cant do are 41/42/43

any help with these appreciated

estoydemoda
Dec19-04, 12:58 AM
5-(2)(2)(1)=1
5-[2+(2-1)]=2
5-[(2/2)+1]=3
(5-1)+2-2=4
12-(5+2)=5
5+(2/2)(1)=6
5+(2/2)+1=7
5+2+(2-1)=8
5+(2+2)1=9
5+2+2+1=10
5(2)+(2-1)=11
5(2)+2(1)=12

estoydemoda
Dec19-04, 01:05 AM
are you allowed to use trig functions? not that it would necessarily help
in fact i doubt it would

estoydemoda
Dec19-04, 01:27 AM
im assuming they cannot be used more than once because you could just say:
5*2*2*2+1

estoydemoda
Dec19-04, 01:33 AM
hahaha [5!/(2+1)]+2=42

futb0l
Dec19-04, 01:45 AM
im assuming they cannot be used more than once because you could just say:
5*2*2*2+1

lol if it could be used more than once u can just do 1^5-1^2+1.... all the way to whatever and making all numbers you could posibbly want.

tunesurfer
Dec19-04, 03:57 AM
No lol they cant be used more than once - posted this on other sites - maths goodies did best we just need number 41 now and we have one for number 36 that we dont understand but we hope the tutor will .

(((1+5/2)!)^2 = 36

ceptimus
Dec19-04, 08:04 AM
36 = (12 \times .5)^2

41 = \left(\frac{2}{.1} + .5\right) \times 2

ceptimus
Dec19-04, 08:22 AM
51 = 52 + 1 - 2

52 = (25 + 1) \times 2

53 = 52 + 2 -1

54 = 52 + 2 \times 1

55 = 52 + 2 + 1

56 = \frac{\frac{2}{.5(recurring)} + 2}{.1}

57 = 52 + \frac{1}{.2}

58 = 5 \times 12 - 2

59 = 5 \times (12 - .2)

60 = 15 \times 2 \times 2

:tongue2:

dextercioby
Dec19-04, 08:26 AM
36 = (12 \times .5)^2

41 = \left(\frac{2}{.1} + .5\right) \times 2

Good one,ceptimus...It's cheating............... :cry: It sould have been "0" before the dot. :tongue2: There's my share of cheating:
36=[(5-2)!]^{2\cdot1}
41=[5-(2-2)!]1

Daniel.

PS.In the second line,there is no multiplication between 4 and 1. :tongue2:
EDIT: 41=\frac{5}{.(1)}-(2\cdot2)

ceptimus
Dec19-04, 08:31 AM
I couldn't find answers for 69, 79, 83 and 87 but otherwise I have all the numbers up to 113.

Only functions I've used are +, -, *, /, ^, the decimal point, and (recurring)

ceptimus
Dec19-04, 08:36 AM
OK then. Without the 0. 'cheat'

36 = 12 \times (5 - 2) D'Oh!

dextercioby
Dec19-04, 08:40 AM
I couldn't find answers for 69, 79, 83 and 87 but otherwise I have all the numbers up to 113.

Only functions I've used are +, -, *, /, ^, the decimal point, and (recurring)

69=(5+2)1-2

Daniel.

ceptimus
Dec19-04, 08:48 AM
69=(5+2)1-2

Daniel.

You're not seriously expecting anyone to accept that 71 = (5+2)1 is an acceptable notation are you? :yuck: :rofl:

tunesurfer
Dec19-04, 08:50 AM
These are the answers we came up with mostly by ourselves and with help from this forum - while we have checked these they may not all be correct - tutor will mark this week. Number 44 was a double factorial and we hope this is legal (as well as the .5 in number 41 lol). The alternatives where afterthoughts while checking when typing.

1- 5-(2+2)x1
2- 5-(2+2)+1
3- 5-2x1^2
4- 5-(1+2)+2
5- (5x1)+2-2
6- 5+1+2-2
7- 5+2x1^2
8- 5+1^2+2
9- (5+2^2)x1
10- 5+2+2+1
11- 5+(2x(2+1))
12- (2x5)+2x1
13- (2x5)+2+1
14- (5+1)x2+2
15- (5+2)x2+1
16- (5+2+1)x2
17- (2+1)x5x2
18- ((2x2)!)-5-1
19- 5x(2+2)-1
20- 5x(2+2)x1
21- 5x(2+2)+1
22- ((5x2)+1)x2
23- 5^2-2x1
24- (2x2)x(5+1)
25- 5x(2+2+1)
26- 5^2-2+1
27- 25+2x1
28- 25+2+1
29- (((2+2)!)+5)x1
30- (5x(2+1))x2
31- ((2+5)!!!)+2+1 alternative ((5!)/(2+2))+1
32- 15x2+2 alternative((5-1)^2)x2
33- 2^5+2-1
34- (5+1)^2-2
35- 2^5+2+1
36- (((1+5)/2)!)^2
37- 21x2-5
38- (5+1)^2+2
39- 5!/2-21
40- 2^(2+1)x5
41- (21-.5)x2
42- (5+2)x((2+1)!)
43- 2x21.5
44- ((5+1)!!)-2-2
45- (2+1)^2x5
46- ((5-1)!)*2-2
47- 21x2+5
48- (5+2)^2-1
49- 25x2-1
50 25x2x1

alternative to 41/44 welcome just in case
Many thanks to all who helped and a Happy Xmas and New Year to all from here in the UK.

ceptimus
Dec19-04, 08:54 AM
44 = 2^5 + 12

see other answers above.

dextercioby
Dec19-04, 09:42 AM
You're not seriously expecting anyone to accept that 71 = (5+2)1 is an acceptable notation are you? :yuck: :rofl:

I would call that an identity.At least in the decimal basis... :approve:
Read and weep:
41=[(2+1)!]^{2} +5 :tongue2:

Daniel.

estoydemoda
Dec19-04, 09:54 AM
beautifully done dexter