Mathematic problem
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I'm stuck on a problem that maybe most of you will be able to solve instantly. Here is the problem:
A publisher needs to bind $4500$ books. One print shop can bind these books in $30$ days, another shop can do it in $45$ days. How many days are necessary to bind all the books if both shops work in parallel?
The problem's answer is $18$ days, but I got $13$ days. Here is how I calculated this:
First, I found the books per day for each shop:
Shop 1 = $frac{4500}{30} $ = $150$ books/day
Shop 2 = $frac{4500}{45}$ = $100$ books/day
Let $x$ be the number of days:
$$150x + 100x = 4500$$
$$x = 4500 / 350 = 12.8$$ or $13$ days
What am I missing here? Thanks
algebra-precalculus arithmetic problem-solving
edited Nov 17 at 16:19
klirk
2,220428
asked Nov 17 at 16:10
E-Kami
1294
add a comment |
up vote
2
down vote
favorite
I'm stuck on a problem that maybe most of you will be able to solve instantly. Here is the problem:
A publisher needs to bind $4500$ books. One print shop can bind these books in $30$ days, another shop can do it in $45$ days. How many days are necessary to bind all the books if both shops work in parallel?
The problem's answer is $18$ days, but I got $13$ days. Here is how I calculated this:
First, I found the books per day for each shop:
Shop 1 = $frac{4500}{30} $ = $150$ books/day
Shop 2 = $frac{4500}{45}$ = $100$ books/day
Let $x$ be the number of days:
$$150x + 100x = 4500$$
$$x = 4500 / 350 = 12.8$$ or $13$ days
What am I missing here? Thanks
algebra-precalculus arithmetic problem-solving
edited Nov 17 at 16:19
klirk
2,220428
asked Nov 17 at 16:10
E-Kami
1294
150 + 100 = 250, not 350...
– Gautam Shenoy
Nov 17 at 16:14
$150 + 100 = 250 neq 350$
– Praneet Srivastava
Nov 17 at 16:14
I'm an idiot, thanks guys
– E-Kami
Nov 17 at 16:25
add a comment |
up vote
2
down vote
favorite
up vote
2
down vote
favorite
I'm stuck on a problem that maybe most of you will be able to solve instantly. Here is the problem:
A publisher needs to bind $4500$ books. One print shop can bind these books in $30$ days, another shop can do it in $45$ days. How many days are necessary to bind all the books if both shops work in parallel?
The problem's answer is $18$ days, but I got $13$ days. Here is how I calculated this:
First, I found the books per day for each shop:
Shop 1 = $frac{4500}{30} $ = $150$ books/day
Shop 2 = $frac{4500}{45}$ = $100$ books/day
Let $x$ be the number of days:
$$150x + 100x = 4500$$
$$x = 4500 / 350 = 12.8$$ or $13$ days
What am I missing here? Thanks
algebra-precalculus arithmetic problem-solving
edited Nov 17 at 16:19
klirk
2,220428
asked Nov 17 at 16:10
E-Kami
1294
I'm stuck on a problem that maybe most of you will be able to solve instantly. Here is the problem:
A publisher needs to bind $4500$ books. One print shop can bind these books in $30$ days, another shop can do it in $45$ days. How many days are necessary to bind all the books if both shops work in parallel?
The problem's answer is $18$ days, but I got $13$ days. Here is how I calculated this:
First, I found the books per day for each shop:
Shop 1 = $frac{4500}{30} $ = $150$ books/day
Shop 2 = $frac{4500}{45}$ = $100$ books/day
Let $x$ be the number of days:
$$150x + 100x = 4500$$
$$x = 4500 / 350 = 12.8$$ or $13$ days
What am I missing here? Thanks
algebra-precalculus arithmetic problem-solving
algebra-precalculus arithmetic problem-solving
edited Nov 17 at 16:19
klirk
2,220428
asked Nov 17 at 16:10
E-Kami
1294
edited Nov 17 at 16:19
klirk
2,220428
asked Nov 17 at 16:10
E-Kami
1294
edited Nov 17 at 16:19
klirk
2,220428
edited Nov 17 at 16:19
klirk
2,220428
edited Nov 17 at 16:19
klirk
2,220428
2,220428
asked Nov 17 at 16:10
E-Kami
1294
asked Nov 17 at 16:10
E-Kami
1294
asked Nov 17 at 16:10
E-Kami
1294
1294
150 + 100 = 250, not 350...
– Gautam Shenoy
Nov 17 at 16:14
$150 + 100 = 250 neq 350$
– Praneet Srivastava
Nov 17 at 16:14
I'm an idiot, thanks guys
– E-Kami
Nov 17 at 16:25
add a comment |
150 + 100 = 250, not 350...
– Gautam Shenoy
Nov 17 at 16:14
$150 + 100 = 250 neq 350$
– Praneet Srivastava
Nov 17 at 16:14
I'm an idiot, thanks guys
– E-Kami
Nov 17 at 16:25
150 + 100 = 250, not 350...
– Gautam Shenoy
Nov 17 at 16:14
150 + 100 = 250, not 350...
– Gautam Shenoy
Nov 17 at 16:14
$150 + 100 = 250 neq 350$
– Praneet Srivastava
Nov 17 at 16:14
$150 + 100 = 250 neq 350$
– Praneet Srivastava
Nov 17 at 16:14
I'm an idiot, thanks guys
– E-Kami
Nov 17 at 16:25
I'm an idiot, thanks guys
– E-Kami
Nov 17 at 16:25
add a comment |
1 Answer
1
active
oldest
votes
up vote
2
down vote
accepted
You have somehow gotten $350$ from adding $100$ and $150$. It should be $250$ only.
answered Nov 17 at 16:14
Henning Makholm
236k16300534
I'm so stupid, thanks a lot...
– E-Kami
Nov 17 at 16:25
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
2
down vote
accepted
You have somehow gotten $350$ from adding $100$ and $150$. It should be $250$ only.
answered Nov 17 at 16:14
Henning Makholm
236k16300534
I'm so stupid, thanks a lot...
– E-Kami
Nov 17 at 16:25
add a comment |
up vote
2
down vote
accepted
You have somehow gotten $350$ from adding $100$ and $150$. It should be $250$ only.
answered Nov 17 at 16:14
Henning Makholm
236k16300534
I'm so stupid, thanks a lot...
– E-Kami
Nov 17 at 16:25
add a comment |
up vote
2
down vote
accepted
up vote
2
down vote
accepted
You have somehow gotten $350$ from adding $100$ and $150$. It should be $250$ only.
answered Nov 17 at 16:14
Henning Makholm
236k16300534
You have somehow gotten $350$ from adding $100$ and $150$. It should be $250$ only.
answered Nov 17 at 16:14
Henning Makholm
236k16300534
answered Nov 17 at 16:14
Henning Makholm
236k16300534
answered Nov 17 at 16:14
Henning Makholm
236k16300534
answered Nov 17 at 16:14
Henning Makholm
236k16300534
236k16300534
I'm so stupid, thanks a lot...
– E-Kami
Nov 17 at 16:25
add a comment |
I'm so stupid, thanks a lot...
– E-Kami
Nov 17 at 16:25
I'm so stupid, thanks a lot...
– E-Kami
Nov 17 at 16:25
I'm so stupid, thanks a lot...
– E-Kami
Nov 17 at 16:25
add a comment |
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150 + 100 = 250, not 350...
– Gautam Shenoy
Nov 17 at 16:14
$150 + 100 = 250 neq 350$
– Praneet Srivastava
Nov 17 at 16:14
I'm an idiot, thanks guys
– E-Kami
Nov 17 at 16:25