simple maths problems?

I am afraid the previous answers are all wrong..
The area of the actual door is 8x50x50 square cm. . Scale refers to linear measurements so if the model door is 2cm by 4cm then the actual door is 100 cm x 200cm which is 2x50x4x50.
The second question is meaningless without further Information but 1.24 would be a good guess!
SORRY . Now there are two correct answers above mine!

It depends on the dimensions of the door - for instance, if the door was 4cm high by 2 cm wide then the area would be 8 square cms. But multiply by a ratio of 50 and you get a door 200cm by 100 cm and the area would now be 20,000 square cms.
Do those people who are telling you the answer is 400 square cms honestly believe that the door through which they go in to school is 20cm by 20cm? They must be really tiny people!!

To two decimal places, 1.24 would be accurate enough.

For areas, you'll need to multiply by 50^2 = 2500. To remember this, though, I used to do this:

Consider the door as a square. Thus the sides are sqrt(8) = 2.828...
Now, multiply by 50 to get the sides of the real (albeit square) door. So the real door has sides of sqrt(8)*50 = 141.42...

Now, to find the area, square it! The door has area 20000cm^2.

This isn't a very useful answer, so you may divide by 10000 to get it into m^2. Again, you can just divide the lengths of the sides by 100 to get them into meters.

Thus the sides of the door are 1.4142... which, when squared, gives an area of 2m^2.

As for the second question, it depends upon what you've been taught as an appropriate degree of accuracy, but generally 3 significant figures is about right. This means you should only use the first three NON-ZERO digits, remembering to round the third. So you should probably use 1.24.

Hope this helps.

Edit: The real door is not 400cm^2. This would imply that the real door has sides of only 20cm if it's a sqare, or it's, say 40cm high and 10cm wide! Not a very big door! Remember, when you're scaling, you scale EACH SIDE by 50, making the area 2500 times bigger.

Also, when I said the first NON-ZERO digits, I meant the first 3 digits counting from the first non-zero digit. Thus 2.000345 would be 2.00 to 3s.f., but 0.00023463 would be 0.000235 to 3s.f.

1) You have the ratios-

1:50
8:x

x = 8 * 50 = 400cm²

2) 2.d.p should be sufficient, so 1.24

1) the scale is 1:50 so you multiply whatever value you have by 50 so 8cm * 50 is 400cm squared.

2) I have no idea what that's asking for, I'm guessing it's simplifying if it is then, you do it to 1 decimal place i.e. 1.240... would become 1.2.

:D

Next time do your own homework though - it's for your own good :D

I would say 1= 8x 50= 400 cm
2 = 1.24

1.) if jim is using it on 1:50th of a scale that means you must take the #'s and multiply them by 50. Ex. 8x50 there is your answer
2) i honestly dont know what degree's are. I am barely a 7th grader

im not sure but i think . . .

ok so the scale is 1:50. so to get the original area, times the area on the model by 50. the answer is 8x50=400.

i dont know the 2nd soz, i think its something to do with rounding. hope this helped :)

dunno abotu 2 but just do 8 x 50 for the 1st