A student obtains 75%, 80% and 85% in three subjects.If the marks of another subject is added, then his average cannot be less than
60%
65%
80%
90%
Marks obtained from three subjects out of 300 is 75 + 80 + 85 = 240
If the marks of another subject is added, then the marks will be ≥240 out of 400.
.'. Minimum average marks =2404=60% (when marks in the fourth subject is 0)