Sentence Correction Question from GMAC: Rate of vs Rate times

Question

I remember on one of my GMAC Question of Day I got an SC question that made me choose between:

Trees grow  at a rate of five times that  of flowers.

Trees grow  at a rate five times the rate  of flowers.

Are there any guidelines on that or they both correct?

Source: GMAC Question of Day

DinkarDK · Answer

At a rate of - is incorrect usage.

oasis90 · Answer

I have seen rate of so many times while reading. Rate of 5% or any percentage

abhinashgc · Answer

BrightOutlookJenn · Answer

Hi  oasis90 ,

at a rate of (exact rate) => at a rate of 5%, at a rate of 10 cents per mile, at a rate of 40 km/h, at a rate of a foot per year
at a rate (comparison: x times/double/triple) => cats age at a rate three times that of dogs, paintings appreciate at a rate 10 times that of sculptures

So, in your example, "at a rate of five times that ..." is wrong because this is a comparison, not an exact rate.

Best, Jennifer

oasis90 · Answer

Jennifer. Thank you for the great explanation.

piyush93 · Answer

For comparisons, we use at a rate x times the rate..

Sentence Correction Question from GMAC: Rate of vs Rate times

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