Question

To the nearest foot, how long is Pennsylvania Ave. between 19th St. and 18th St? (Hint: The 425 ft on the map above represents the length of Pennsylvania Ave. between 20th St. and 19th St.

Answer 1

use a ratio between penn ave and 1st st

Answer 2

okay so would that be the 425 @phi ? sorry if thats a dumb question..

Answer 3

ratio means fraction. they give you penn and 1st ave (between 20th and 19th)
make that a fraction

now make a fraction of penn (use x for unknown) and 1st between 19th and 18th

those fractions are =
can you write down the fractions ?

Answer 4

yeah Okay I knew they where fractions but the numbers i was confused on okay so the numbers up in the corners before the streets are those the ones to use?

Answer 5

yes

Answer 6

Okay so 19th would be 380 and 18th would be 500 @phi

Answer 7

yes, but we need ratios. (with penn ave)
the length of penn between (20 and 19) "goes with" the length of 1st between 20 and 19. write that as a fraction
what do you get ?

Answer 8

im sorry okay I get that its 380/ first street but what number is first like the length? @phi

Answer 9

oh wait is is 425/380? @phi

Answer 10

because the length between 20 and 19 is 423

Answer 11

*425

Answer 12

yes 425/380

now the same thing for the next block over
but we don't know penn ave so use x for penn aves #

Answer 13

okay so its gonna be 425/380 and 500/x?

Answer 14

almost. you want the numbers in the correct order: penn to 1st ave
in both fractions.

Answer 15

or penn divided by 1st

Answer 16

okay so its 425/380 and 425/x ?? that seems wrong like the number i picked @phi

Answer 17

yeah thats wrong..cause the answer I would get wouldnt be an option so what number is penn? im confused...

Answer 18

wait its first I gotta get cause we dont know penn

Answer 19

you had the right #'s to begin with... penn (between 18 and 19) is x
1st between 18 and 19 is 500

you want both of your fractions to be penn divided by 1st

Answer 20

but whats first? Im running out of time to do this :o

Answer 21

I have like 5 mins okay so its

Answer 22

425/380 then what?

Answer 23

425/380 is penn/ 1st (right?)
now do the same thing for the next block over
set those fractions equal to each other.
what do you get?

Answer 24

the next street over would be 500/x

Answer 25

500 is 1st street's length you have it upside down

Answer 26

what number is it I am so lost right now im looking at the page so it would be 600?

Answer 27

oh dear gosh i have 2:20 left

Answer 28

you said
**the next street over would be 500/x**

that is upside down.... you want both fractions to be penn divided by 1st
500 is 1st and x is penn so you have 1st / penn. That is upside down

Answer 29

what? okay times up so...

Answer 30

@hartnn please get rid of the spammer

Answer 31

well thanks @phi for the help I will have to try and retake the assignment later cause I didnt pass but thank you anyway

Answer 32

This stuff sinks in better if you are not under time pressure. However, it would be good to try to finish the problem. Once you learn it, it is easy to pass the test.

Answer 33

I know it would be better not under a times but i dont get the option.