If x + y = 11 and xy = 24, then x² + y² is equal to

1. 121

2. 73

3. 48

4. 169

The value of 249² - 248² is

1. 1²

2. 477

3. 487

4. 497

If a + b + c = 0, then the value of a³ + b³ + c³ is

1. 0

2. abc

3. 2abc

4. 3abc