multiply the first three digits of your phone number with 80, then add 1 next multiply by 250, and the last four digits of your phone number two times, then subt 250 and divide by 2. it comes out to be your phone number...
2007-04-10 12:25:53 · 5 answers · asked by ? 1 in Science & Mathematics ➔ Mathematics
take any three digit number x, and four digit number y
your formula = ((x*80 + 1)*250 + 2y -250)/2
= (x*20000 + 250 +2y -250)/2
= x*10000 + y
your phone number is abc*10000 +defg
so it has to give you the number back
2007-04-10 12:31:35 · answer #1 · answered by hustolemyname 6 · 2⤊ 0⤋
Let the 1st 3 digits be A, and remember they're in the 10,000's place; let the last 4 be B. So your number is 10,000A + B.
The directions say:
[(80A + 1)250 + 2B - 250] / 2 =
[20,000A + 250 + 2B - 250] / 2 =
[20,000A + 2B] / 2 =
10,000A + B
2007-04-10 19:34:22 · answer #2 · answered by Philo 7 · 0⤊ 0⤋
These types of problems 'work' this way :
Consider this one.
Take the first digit of a two-digit number. Multiply it by ten and then add the second digit. You should now have the original two digit number.
See how it worked?
2007-04-10 19:35:07 · answer #3 · answered by chancebeaube 3 · 0⤊ 0⤋
Are you sure this is correct? This didn't work for me.
2007-04-10 19:29:37 · answer #4 · answered by peersignal 3 · 0⤊ 2⤋
i don't think that works...you probably just typed it in wrong.
2007-04-10 19:34:08 · answer #5 · answered by chunew21 2 · 0⤊ 1⤋