ok part 1 ur basically making the expression there are 25 so say he attempts 20 of them and gets 18 right he would be tallied with 72 marks then u minus the ones he didn't answer leaving him with 65 or in other simpler terms 25-20 then u add the tallies he has then which equals -5 with 18 right that makes +72 so the 67 and then subtract those that are wrong ( 2) which is the final answer of 63
Part 2 55/ 4= 13 yes I realized it not 55 but 52 ok so basically u stuck with 3 left leaving u with 1 wrong and 1 unattempted leaving u with 55 tallies
