can singular be used with compound subject

[dps]

I came across a question whose correct answer was using singular for compound subject.

Is it correct or some problem with the answer?

Correct answer:
Great news in the world's poorest countries is that the amount of arable land and the average crop yield per acre is increasing

Should it be "are increaing", considering subject is "amount of ar... and the avg crop yield"?

Will appreciate if someone can explain this..

[naagi]

I came across a question whose correct answer was using singular for compound subject.

Is it correct or some problem with the answer?

Correct answer:
Great news in the world's poorest countries is that the amount of arable land and the average crop yield per acre is increasing

Should it be "are increaing", considering subject is "amount of ar... and the avg crop yield"?

Will appreciate if someone can explain this..


Here the [b]amount[/b] is uncountable and so it has to be singular .

[dps]

I think the subjects are: "the amount of arable land" & "the average crop yield per acre"

If "amount" is subject, it means "the average crop yield" is linked to "the amount", but "the amount of the average crop yield per acre" doesn't make any sense

[StaceyKoprince]

No, that should be "are increasing." You've got a compound subject. That rule is pretty hard-and-fast.

Where did you see this problem?

[dps]

Stacey, thanks for clearing this doubt
It's been a while that I worked on this problem, so don't exactly remember where

[JonathanSchneider]

I'll leave this one up here for now. Even though you didn't list the source, just since the original question was not posted in full. But in the future, please post the source for every qusstion.