Total students = 40
If 75% of the students weights 140 pounds, then (100 - 75) = 25% weighs more than 140 pounds.
So,
Students above 140 pounds = 25% of 40
Students above 140 pounds = (25 / 100) * 40
Students above 140 pounds = (1 / 4) * 40
Students above 140 pounds =10
So, 10 students weighed more than 140 pounds