Jennifer has a set of tiles that are all the same size. She arranges them in a retangular design that has a perimeter of 38 tiles. Which choice could be the number of tiles she has?
A. 24 B. 48 C. 36 or D. 52
2007-10-08 14:05:30 · 7 answers · asked by Miss Pleo 2 in Science & Mathematics ➔ Mathematics
if it has a perimeter of 38 tiles, the answer must be at least 38, so that leaves out answer A and answer C. for answer B. the factors that could work are 3 and 16, since 16*2 = 32 and 3*2 = 6 and 32+6=38, and the number of blocks would be 3*16 which is 48.
but I would like you to know how I got this. the thing is, a perimeter is the sum of all sides, where as the area (total number of tiles) is l*w or length times width, or as some like to call it, the product of two adjecent sides. so, if you know the perimeter, then you just need to find the factors (the possible lengths for the sides) and some factors that work, are 3*2 + 16*2 (since it is a rectangle, two sides are congruent and another two sides are congruent. thats why we multiply each side by 2, since there are two of them) and that works for 38, now to do l*w, and that is 16*3=, and that, of course, is 48.
so the answer is B. 48
2007-10-08 14:11:29 · answer #1 · answered by Tarnation 2 · 4⤊ 2⤋
Right off the bat 24 and 36 are right out. You cannot have more tiles around the perimeter than the total number.
If we assume the tiles are square, then we know a rectangle formed by 48 times will be 1 by 48 (Perimeter 48), 2 by 24 (Perimeter 48. Still only edge tiles), 3 by 16 ( Now the border will be the sum of the sides - 4 to avoid double counting tiles. 16 + 16 + 3 + 3 - 4 = 34 {This is in fact the answer they want, because they do double count the corner tiles, but we'll pretend we didn't know that}), 4 by 12 (Perimeter 4 + 4 + 12 + 12 - 4 = 28), or 6 by 8 (Perimeter 6 + 6 + 8 + 8 - 4 = 24). None work.
A rectangle formed by 52 tiles will be 52 by 1 (Perimeter 52), 26 by 2 (Perimeter 52), 4 by 13 (Perimeter 4 + 4 + 13 + 13 - 4 = 38). So they don't work either.
2007-10-08 14:17:54 · answer #2 · answered by Edgar Greenberg 5 · 1⤊ 3⤋
Convert all mixed numbers to unsuitable fractions then do the operations (including, subtracting) 27/7 - 17/7 + 33/7 = (27-17+33)/7 = 40 3/7 = 6 a million/7 you're able to do a similar element a distinctive way by employing subtracting and including the whole numbers separately from the fractions as so: 3 6/7 - 2 3/7 +4 5/7 ---------- 5 8/7 OR 6 a million/7
2016-10-21 12:38:59 · answer #3 · answered by Anonymous · 0⤊ 0⤋
depending on how old your son is this seems like a really awful question
knowing that perimeter is 2(l+w)=38
you can say that l + w = 19
from there you can make a list of possible dimenensions and then take the area, which is the total number of tiles
remember area of a rectangle is l*w
1 + 18 = 19 1*18= 18
2+17=19 2*17 = 34
3+16= 19 3*16=48 answer b
and that gives you an answer that works you can keep going but nothing else works
hope this helps =D
2007-10-08 14:14:21 · answer #4 · answered by Geno 2 · 1⤊ 2⤋
C. 36
Explanation- well the dimentions of the rectangle could be 17, 17, 2, and 2. which all add up to 38. to find out how many tiles are i this figure, u would multiply 17 and 2 to get 36. so that's why the answer is 36!
2007-10-08 14:13:39 · answer #5 · answered by monsteraddict4690 1 · 0⤊ 4⤋
All of them.
Integers answers from 1 to infinity are valid.
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Tarn. She never told you the tiles are the same length and such. Only same size.
2007-10-08 14:11:39 · answer #6 · answered by UnknownD 6 · 0⤊ 6⤋
No, I won't - and you shouldn't be either.
2007-10-08 14:11:21 · answer #7 · answered by N L 6 · 0⤊ 6⤋