Ineed both parts (a) given a material with an attenuation coefficient (a) of 0.6/cm, what is the intensity of a beam (with an incident intensity, lo) after it has traveled through 1 cm of the material? after it has traveled through 2 cm of the material? (b) what is the optical density of a 1 cm thick piece of such a material? of a 2 cm thick piece of such a material?

more than, less

less than, more

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form

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