HMMT 二月 2000 · 代数 · 第 5 题
HMMT February 2000 — Algebra — Problem 5
题目详情
英文原题
- A ja k et w as originally pri ed $100. The pri e w as redu ed b y 10% three times andin reased b y 10% four times in some order. T o the nearest en t, what w as the nalpri e?
解析
英文解析
- Ev ery da y Edw ard w orks, he gets of the test done. Similarly , ev ery da y Barbara
1 19
w orks, she gets of the test done, ev ery da y Abhina v w orks, he gets of the test
10 11
done, and ev ery da y Alex w orks, he gets of the test done. So, after 4 da ys (after 1
1 1 1 112
ev ery one has w ork ed on the test one da y , they have ompleted + + + = 38 : 535%
9 10 11 12
of the test. After 8 da ys, they have ompleted t wi e that, or 77 : 0707% of the test. After
Edw ard, Barbara, and Abhina v each w ork one more da y , the test will be omplete inthe minim um amoun t of time, so the test will tak e 11 da ys to omplete. If the leasteÆ ien t w ork ers w ork after the 8 th da y , the test still tak es 11 da ys to omplete.
2 4 8 12 24 25 50 100 200