Question

Look at the table. Make a conjecture about the sum of the first 10 positive even numbers

here is the table
2=2=1x2
2+4=6=2x3
2+4+6=12=3x4
2+4+6+8=20=4x5
2+4+6+8+10=30=5x6

The sum is 10 × 11.
The sum is 10 × 10.
The sum is 11 × 12.
The sum is 9 × 10.