Question

i am confused back to this way, the answer should be 108 right? http://gyazo.com/6fc7a19c108256ce232f25f694806cdf

Answer 1

\[\frac{ 12 }{ 1 } = \frac{ x }{ 9 }\]

Answer 2

still confused...

Answer 3

Okay, so if a parasite is 1cm, then it is 12 units big in real life, correct?

Answer 4

yes @cormacpayne

Answer 5

is it 12*9?

Answer 6

It is! And you get that answer by setting up a ratio like the one I provided above.

Answer 7

so 12*9=108

Answer 8

Correct!

Answer 9

so thats my answer?

Answer 10

Yup!

Answer 11

it was wrong..

Answer 12

http://gyazo.com/774982b8e85935d16204983a97ac4019

Answer 13

http://gyazo.com/218c904f6e454c35bd0e4abc8594ddfd so here is another one, the answer should be 18000 correct?

Answer 14

Then we read the problem incorrectly. The new ratio would look like:
\[\frac{ 12 }{ 1 } = \frac{ 9 }{ x }\]
Since the larger image would be what we see, the real life image would be smaller than that.

Answer 15

doesnt help at all...

Answer 16

The 12:1 ratio represents the ratio of the size of the parasite that we see to it's actual size. So if we look in the microscope and see that the parasite is 12cm, then we know it is 1cm in real life (because of the ratio). We misread the problem the first time around, and had the ratio mixed up.

They gave us the size of the parasite that we see (9cm) and ask us to find what it's actual size is. So we would set up proportions like the one I had above and solve for x.

Answer 17

http://gyazo.com/218c904f6e454c35bd0e4abc8594ddfd can you try to help with this?

Answer 18

Okay, so it's the same idea of ratios and proportions. On the map, 1km is represented by 15,000 cm, right?

Answer 19

ya

Answer 20

Okay, good! So now we know that he walked 1.2km, so we can set up a proportion to figure out the number of centimeters:
\[\frac{ 1 }{ 15,000 } = \frac{ 1.2 }{ x }\]

Answer 21

so 15k*1.2

Answer 22

=18000

Answer 23

Correct!

Answer 24

it was wrong....!