In the 1980’s the rate of increase of the minority population of the United States was nearly twice as fast as the 1970’s.
(A) twice as fast as
the rate of increase in the 1980's was nearly twice as fast as the 1970's
(B) twice as fast as it was in
the rate of increase in the 1980's was nearly twice as fast as it was in the 1970's
(C) twice what it was in
the rate of increase in the 1980's was nearly twice what it was in the 1970's
(D) two times faster than that of
the rate of increase in the 1980's was nearly two times faster than that of the 1970's
(E) two times greater than
the rate of increase in the 1980's was nearly two times greater than the 1970's

My answer: E
rate is a speed, so have to use greater/lesser. c.f. "high speed" vs "fast speed"

sogmat wrote:In the 1980’s the rate of increase of the minority population of the United States was nearly twice as fast as the 1970’s.
(A) twice as fast as
(B) twice as fast as it was in
(C) twice what it was in
(D) two times faster than that of
(E) two times greater than

OA C

Please explain each option

Ok, I'm seeing why it should be C now.
C and E are the only ones that don't use "fast speed".
C: the rate of increase in the 1980's was twice what it was in the 1970's
compares (rate of increase in 1980's) to the (rate of increase in the 1970's)
E: the rate of increase in the 1980's was two times greater than the 1970's
compares (rate of increase in the 1980's) to (1970's) which doesn't make any sense. what aspect of the 1970's was being compared to the "rate of increase" aspect of the 1980's?

sogmat wrote:In the 1980’s the rate of increase of the minority population of the United States was nearly twice as fast as the 1970’s.
(A) twice as fast as
(B) twice as fast as it was in
(C) twice what it was in
(D) two times faster than that of
(E) two times greater than

OA C

Please explain each option

(A) twice as fast as
Since "as....as" is used to show similarity....so this is wrong....here we are doing the comparison.
(B) twice as fast as it was in
Since "as....as" is used to show similarity....so this is wrong....here we are doing the comparison.
(C) twice what it was in
Correct
(D) two times faster than that of
faster and rate of increase together IMO are redundant....
(E) two times greater than
Compares rate with "of 1970"...we need somepronoun to refer to rate...

We can kick out "D" for another reason....incorrect usage of "of"....

of + possessive is wrong....since of + noun makes complete possesive.

Eliminate A, B, and D. We aren't talking about how fast the rate was, but what the rate itself was. Eliminate E, since parallelism isn't maintained; something can't be compared to the speed of the 1970s. We are therefore left with B.