Hi Renchinjav,The confusion is treating "3 women left" and "the number of women doubled" as one linked event. They aren't. They are
two separate things that happen one after another, in order. Read the story as a timeline and handle each step by itself.
Here is the sequence for the women, straight from the wording several posters used (
5x women to start):
-
Start: women =
5x-
Then 3 women leave: women =
5x − 3-
Then (a later, separate moment) the count doubles: women =
2 × (5x − 3)The men's line pins down x:
4x + 2 = 14, so
x = 3.
Now just walk the women's timeline with x =
3:
- Start: 5 × 3 =
15- After
3 leave: 15 - 3 =
12- After doubling: 12 × 2 =
24So the doubling doesn't come
from the
3 leaving - it's simply the
next event in the story (imagine that many new women then walk in, matching the current group). You apply it
after you've already subtracted the
3. That's why the answer is
24 (D), not
12.
Quick way to lock in the habit: whenever a problem says "Then... then... then...," process the changes strictly left to right, one at a time, and never merge two of them. Try this mini-version: a shelf has
6 books, then
2 are removed, then the count triples. How many now? Do it in order:
6 →
4 →
12. Same skill - each "then" is its own step.
Answer: DRenchinjav
I am confused when 3 women left lead the number of women doubled.