Bob got an elevator.He rode up 7 floors, down 5 floors, up 3 floors, up1 floor, and then down 2 floors. He got of the elevator at the eighth floor. On what floor did he start??
2007-09-13 08:33:53 · 5 answers · asked by :) Miss Hockey Lover :) 4 in Science & Mathematics ➔ Mathematics
Alrighty then, Bunny. This is kind of like a maze. Just start backwards (Pretend he's leaving work.):
Bob gets back on the elevator at the eighth floor then goes up two. He is now on the tenth floor. After that he goes down one to the ninth, then down three more to the sixth. He goes five more floors up and arrives on the eleventh floor, then goes back down seven floors. Therefore, he started on the fourth floor.
Hope it helps you. :)
2007-09-13 08:49:27 · answer #1 · answered by Genie 2 · 0⤊ 0⤋
x = floor he started on.
Then x+7-5+3+1-2=8
x+4 = 8
x = 4
2007-09-13 15:44:51 · answer #2 · answered by ironduke8159 7 · 0⤊ 0⤋
call "x" his starting point. let's say up is positive and down negative. we know wherever he went he ended up on the eighth floor.... which means hihs starting point plus whatever he did = 8. so,
x + 7 - 5 + 3 +1 = 8
then you can simplify the left hand side so that you have,
x + 6 = 8
now you can just solve for x and that is where he started
2007-09-13 15:55:06 · answer #3 · answered by bsteale83 1 · 0⤊ 0⤋
he started on the 4th floor.
2007-09-13 15:41:58 · answer #4 · answered by sknymnie 6 · 0⤊ 0⤋
4th Floor!
Do the problem backwards to figure it out.
After you have your answer you can check it.
That was a fun one...
2007-09-13 15:44:02 · answer #5 · answered by David S 1 · 0⤊ 0⤋