was vs were

[Nami Nami]

Dear Teacher,

Which of the following is/are correct?

1. In the 1970s there were an increasing number of demonstrations, clashes between students and the security forces ...

2. In the 1970s there was an increasing number of demonstrations, clashes between students and the security forces ...

3. There were an increasing number of people playing golf who had a disability ...

4. there was an increasing number of people playing golf who had a disability ...

Thanks.

[Alan]

1 & 3.

'A number of' always determines a plural noun phrase, which naturally requires a plural verb.