Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Year | Entrant | Chassis | Engine | Points |
| --- | --- | --- | --- | --- |
| 1950.0 | Bob Gerard | ERA B-type | ERA | 0.0 |
| 1950.0 | Bob Gerard | ERA A-type | ERA | 0.0 |
| 1951.0 | Bob Gerard | ERA B-type | ERA | 0.0 |
| 1953.0 | Bob Gerard | Cooper T23 | Bristol | 0.0 |
| 1954.0 | Bob Gerard | Cooper T23 | Bristol | 0.0 |
| 1956.0 | Bob Gerard | Cooper T23 | Bristol | 0.0 |
| 1957.0 | Bob Gerard | Cooper T43 | Bristol | 0.0 |
Question:
What year has an ERA engine and an ERA A-type chassis?
Answer:
1950.0