Ashok secured average of 70 marks in 6 subjects. If the average of marks in 5 subjects is 74, how many marks did he secure in the 6th subject? Answers:
A) 50  B) 74  C) 78  D) 80  E) none of these

Rationale: "explanation : number of subjects = 6 average of marks in 6 subjects = 70 therefore total marks in 6 subjects = 70 * 6 = 420 now , no . of subjects = 5 total marks in 5 subjects = 74 * 5 = 370 therefore marks in 6 th subject = 420 – 370 = 50 answer a"
Answer: A