Answer:
395, 400, 405, 410, 415, 420
Explanation:
Martin starts at 300 and counts by fives to 420
To find last 6 numbers , we count backwards.
Here , count by 5's. add 5 to get next number
Last number is 420
To get previous number we subtract 5





Last 6 numbers are 395, 400, 405, 410, 415, 420