I am attempting to select a random sample population from the given set of
values in column B. Of the values in column B, only a specific quantity, as
specified in cells E2, F2, and G2 will be used. In column C I use the
=rand() formula. Then in column D I use the formula
=Rank(D2,$D$2:$D$6)<=$E$2, =Rank(D7,$D$7:$D$12=$F$2,
=Rank(D13,$D$13:$D$16)<=$G$2. A value of "TRUE" returned in column D means
that only those values are my random sample.

Obviously, the shortcoming of this system is that I have to write more than
one formula in column D, each time manually looking to see where the A subset
values end, where the B subset values end, etc..

Here's my question: How can I combine the above 3 formulas into one single
formula?

A B C D E
F G
1 Subset Values =Rand() Sample Pop. A B C
2 A 63 .2343 FALSE 2 3 2
3 A 88 .3433 FALSE
4 A 56 .6522 TRUE
5 A 45 .4355 FALSE
6 A 94 .8622 TRUE
7 B 48 .3545 FALSE
8 B 69 .6251 TRUE
9 B 53 .1245 FALSE
10 B 62 .7532 TRUE
11 B 71 .9811 TRUE
12 B 79 .2722 FALSE
13 C 83 .1452 FALSE
14 C 92 .5864 TRUE
15 C 50 .4291 FALSE
16 C 75 .6291 TRUE