Hacker News new | comments | show | ask | jobs | submit login

If the ball cost $0.10, the bat would need to cost $1.10 (a dollar more than $0.10), which would mean that the pair together would cost $1.20, which we know isn't true. To get the right answer, you have to solve the simple algebra equation in Retric's sibling comment.

For the lily pads, the percentage of the lake covered doubles every day, so the lower bound percentages for the last few days look roughly like this: 12.5%, 25%, 50%, 100%. On the 24th day, you'd have to double in size 24 more times in order to fill the pond, rather than the once it'd take on the 47th day.




Here's how I broke it down.. (which is apparently wrong)

A bat and ball cost a dollar and ten cents.

  Bat + Bal = 1.10
The bat costs a dollar more than the ball.

  Bat = Bal + 1.00
How much does the ball cost?

  Bal = ??
So..

  Bat + Bal = 1.10
  Bat = Bal + 1.00
Therefore

  1.00 + Bal = 1.10
  Bal = .10
  1.00 + .10 = 1.10
This seems logical..

Aside: fuck that script that messes with your copypaste, and the same sentiment to sites that implement it


You're subbing in 1.00 for Bat when you should be subbing in 1.00 + Bal for Bat so that you have 1.00 + Bal + Bal = 1.10


Ahhhhhhh. I see now. Kind of funny how I completely misprocessed the "Bat costs 1.00 more than the ball" bit.

Always hated word problems in school :P




Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | DMCA | Apply to YC | Contact

Search: