1. Where are the hundred dollars I lent you?
Tips: Amounts of money are considered singular.
is
2. Mathematics is a very challenging subject for my daughter.
Correct
3. The police intends to interview all householders for their survey.
Tips: We always use a plural verb with the police.
intend
4. This series of wildlife programmes are beautifully filmed.
Tips: This series is singular.
is
5. The news from overseas aren’t very promising.
Tips: The news is uncountable and takes a singular verb.
isn't
6. Each staff receives a pay rise next year.
Tips: We cannot say a staff.
member of staff
7. Ten years is a long time to be in prison.
Correct
8. We are looking for a means of entering the China market.
Correct
9. There are several thousands of species of butterfly in the world.
Correct
10. Athletics are generally considered an easy option by students.
Tips: Although athletics ends in –s, it is regarded as a singular word.
is