Fill in the missing number:
1260360840240420?
120
For the first two rows:
60÷12=5 and 360÷60=6
40÷8=5 and 240÷40=6
So, we observe that in a row:
Number in the second column = 5 × Number in the first column
Number in the third column = 6 × Number in the second column
So, 5 × 4 = 20 and 6 × 20 = 120
Hence, the missing number is 120.