math (again ugh)
posted by brianna on .
A rectangular place mat and matching napkin are proportional. The dimensions of the place mat are 1.5 times as large as the napkin's dimensions.
If the perimeterof the place mat is 60 in., the perimeter of the napkin is what?
i think i have to divide 60 by 1.5, but i'm not sure baecause the question says the DIMENSIONS, which is comfusing me.
Yes, you are right.
Dimensions are length
so i don't have to multiply 1.5 by 4? i thought i had to because of the dimensions part, and becauseof the fact that the question says "dimensions" i thought it meant plural, as in more than 1.
Every length measurement (in inches or cm or whatever) is 1.5 times. That includes the perimeter in inches.
If they asked for area, the big one would be 1.5*1.5 = 2.25 times
But they did not ask for area.
ohhh. it makes sense now. good thing to , 'cause i wasn't at school for the lecture on my packet my teacher gave me for homework
so if they ask for area, then i'll have to multiply double. iget it thanks. but if you don't mind, i have another question.
Now say the place mat were
L = 20
W = 10
then Perimeter = 2*20 + 2*10 = 40+20 = 60
Then the napkin
L = 20/1.5 = 13 1/3
W = 10/1.5 = 6 2/3
then perimeter = 26 2/3 + 13 1/3 = 40
Notice that 60 = 1.5 * 40 :)
i know how to get perimeter, it's just when the word problems confuse me.
about the question i posted earlier, i get it now that you explained it to me.
Now, just to be mean, let's see what happens to the AREA of the napkin
area placemat = 20 * 10 = 200 in^2
area napkin = 13 1/3 * 6 2/3 = 88 8/9
and notice that
88 8/9 *1.5 *1.5 = 200
that is mean jk lol
ok,so the area of the placemat would be 200 because 20*10=200, but the area of the napkin is that why?
so the area of the napkin is proportional to the place mat i get it that's cool