The distance is 1.47 ...
Then the final distance is1+(18-1) * 3 = 52m.
The distance from A to B is (1+52)* 18/2=477 m.
7. The line number is 1 3 5 7…, which is a arithmetic progression with a tolerance of 2.
Then line 20 has 1+(20- 1)*2=39.
The leftmost number in line 20 is 20*20-39+ 1=362.
The sum of all the figures in line 20 is (362+400)*39/2= 14859.