If you take 7 from 2 times a number , you get 11
Answers
Answer:
be 5.
Federico from Humanitree used algebra:
Subtract 10
Divide by 4
Add 5
If the number was $n$n
You would do
$(n-5) \times4 +10 = $ end number ($x$)(n−5)×4+10= end number (x)
Then the computer would do this operation to get the original value of $n:$n:
$(x-10)\div4 +5 =$ starting number(x−10)÷4+5= starting number
This operation would give you the original results.
Abdullah from Poland wrote a Python program to guess your number:
print("YOUR NUMBER WAS...")
print()
print("Press [ENTER] after you made each move.")
print()
input("Think of a number.")
print()
input("Add 9")
print()
input("Divide it by 4")
print()
input("Subtract 6")
print()
input("Triple it")
print()
input("Subtract 23")
number = float(input("Now, type in number you finished with and then press enter."))
print("Processing...")
answer = (((number + 23) / 3) + 6) * 4 - 9
print("You chose the number %s" % answer)
Leila C and Scarlett K from Westridge School for Girls and KSc from Cheadle Academy sent in interesting sets of instructions which will always give the same result, like in the problem Your Number Is...
If you follow these instructions, will it ever be possible for the computer to work out what number you started from?
These are KSc's instructions:
1. Think of a number: $x$ $\lt\lt\lt$ [Input] numberx <<< [Input] number
2. Add $3$: $x+3$ 3: x+3
3. Double it: $2x+6$ $\lt\lt\lt$ Begin to balance out dividable equation2x+6 <<<Begin to balance out dividable equation
4. Add $4$: $2x+10$ $\lt\lt\lt$ Equation can now be easily divided4: 2x+10 <<<Equation can now be easily divided
5. Divide by $2$: $x+5$ $\lt\lt\lt$ Simplify equation2: x+5 <<< Simplify equation
6. Subtract [original] number from [current] number: $x+5\hspace{2mm}-x$ $\lt\lt\lt$ Balace equation [balancing $x$ with $-x$]x+5−x <<< Balace equation [balancing x with
Answer:
2 × 7 = 14
14 + 11 = 25
so your answer is 25..