In Harry's attic there are 3 spider webs. The first web is twice as large as the second. The 3rd web is 3 inches larger than the 1st web. The combined width of the 3 webs is 1 foot and 6 inches. How long is each web?
Please provide explanation along with answer. Thank you in advance.
The original data is given in terms of area, but the width is not in the same units.
If area 1 = x, then area 2 = 2x and area 3 = x + 3.
If the total area = 18 square inches, then
x + 2x + x + 2 = 18
Then you can solve for x.
4x + 2 = 18
4x = 16
x = 4
I'll answer since this is unanswered, but, I don't think this is how a third grade student is expected to do this problem.
w = width of web
w = size in inches of the 2nd web
2w = size in inches of the 1st web
2w + 3 = size in inches of the 3rd web
1'6" = 18 inches
w + 2w + (2w + 3 ) = 18
5w + 3 = 18
5w = 15
w = 3
1st web = 3 inches
2nd web = 6 inches
3rd web = 9 inches
Total combined width = 18 inches
I would be very interested to learn how a grade 3 teacher would handle this type of question without relying on algebraic methods such as shown above by
PsyDAG and helper.
This sure looks like some fancy advanced grade 3 stuff.
what is symmetry
whats up
you stupid
To solve this problem, let's assign variables to the widths of the second and first webs. Let's call the width of the second web "x" inches.
According to the problem, the first web is twice as large as the second web, so its width would be 2x inches.
The third web is 3 inches larger than the first web, so its width would be (2x + 3) inches.
The combined width of the three webs is given as 1 foot and 6 inches, which is equivalent to 18 inches.
Putting all the information together, we can create an equation to solve for x:
x + 2x + (2x + 3) = 18
Now, let's solve this equation:
5x + 3 = 18
5x = 15
x = 3
So, we have found that the width of the second web (x) is 3 inches.
Therefore, the width of the first web would be 2x = 2(3) = 6 inches.
And the width of the third web would be 2x + 3 = 2(3) + 3 = 9 inches.
So, the lengths of the three spider webs are:
Second web: 3 inches
First web: 6 inches
Third web: 9 inches