David randomly selected 25 out of the total 68 7th grade students in his school and asked them about their favorite food. Of the students surveyed, 13 chose Pizza. Based on the data, how many students in 7th grade would chose pizza as their favorite food?

Twice the sum of a number and 4 is equal to three times the difference of the number and 7. find the number.

If tan2a=cot(a+60), find the value of a, where 2a is an acute angle

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%)