e.
Cross multiply:
1-32. CONDITIONS WHICH MUST BE MET
a.
The numerators must have the same units.
b.
The denominators must have the same units.
c.
Three of the four variables must be known.
(1)
usually the first ratio of the proportion and this ratio is put in proportion to the amount of
For example: If one aspirin tablet contains five grains of aspirin, then how
many grains would be required to make 40 tablets?
(2)
The EXPRESSION OF STRENGTH is "one tablet contains five grains
of aspirin" and should be written as the first ratio of the proportion:
IF 1 tablet =
THEN _____________
5 grains
(3)
Next, assign X its proper place in the second proportion. Because the
question asks, "How many grains?," the X is placed opposite the grains in the first
proportion.
IF 1 tablet
=
THEN _________
5 grains
X grains
(4)
In order for this to be a valid problem, the question has to tell how
many tablets for which we are calculating. The question asks to calculate the number of
grains in 40 tablets, therefore, the 40 tablets will be placed opposite the tablets in the
first ratio.
IF 1 tablet
=
THEN 40 tablets
5 grains
X grains
MD0802
1-36