Pls asap ill give brainliest!

can someone solve this equation tell me how many solutions are possible.. and if there is none possible, how come?

3(x+4) = 3x + 11

Astudent must have an average on five test that is greater than it equal to 80% but less than 90% to receive a final grade of b. devon's greades on the first four test were 78% 62% 91% and 80% what range if grades on the fifth test would give him a b in the course? ( assuming the highest grade is 100%)