If 10K microns = 1 cm = 100m angstroms, how many...?

[Sarah2391]

If 10,000 microns = 1 centimeter and 100,000,000 angstrom units = 1 centimeter, how many angstrom units equals 1 micron?

(a) .000000000001

(b) .0001

(c) 10,000

(d) 100,000

(e) 1,000,000,000

--Please show how to get to answer--

 

[Mrspi]

Re: Help! 1st one

If 10,000 microns = 1 centimeter and 100,000,000 angstrom units = 1 centimeter, how many angstrom units equals 1 micron?

(a) .000000000001

(b) .0001

(c) 10,000

(d) 100,000

(e) 1,000,000,000

--Please show how to get to answer--

You've got TWO expressions, each equal to 1 cm. Set those two expressions equal to each other.

1 cm = 1 cm

10000 microns = 100 000 000 angstrom units

Now...to find out what 1 micron is equal to, divide both sides of the above equation by 10000....

 

[Deleted member 4993]

These are what I call book-keeping problems. You need to read the problem very carefully to ascertain which way you need to go (µm ? Å) and then count zeroes very carefully.

Sometimes there is a danger of getting cross-eyed - while counting zeroes in these problems . So I resort to "power of ten" (still counting zeroes - but once - very carefully).

\(\displaystyle 10^4\) µm = \(\displaystyle 10^8\) Å

so

1 µm = \(\displaystyle 10^4\) Å

Now count zeroes carefully and match your list of answers.