if there are 25 questions +3 for correct -1 for incorrect and someone has scored less than 76 in that case scores like 74, 73 and 70 are not possible why ????

there are 25 questions. If all the answers be correct then score will be 75. If one answer be incorrect then score will be 24×3-1=71.If 24 answers are correct and no incorrect then score will be 72. If two answers be incorrect then score will be 23×3-2=67.... thus there will be no possibility of scoring 74,73,71 and so on