Question 1 with 1 blankricardo y tomás son (the least boring) de la fiesta. question 2 with 1 blankmiguel y antonio son (the worst) estudiantes de la clase. question 3 with 1 blankmi profesor de biología es (the oldest) de la universidad. question 4 with 1 blankella es (the youngest) del grupo.

Question 1: Ricardo y Tomás son los menos aburridos de la fiesta.

Question 2: Miguel y Antonio son los peores estudiantes de la clase.

Question 3: Mi profesor de biología es el más viejo de la universidad.

Question 4: Ella es la más joven del grupo.

Explanation:

Superlatives are formed as follows:

Singular male subject:

"El más" + adjective (singular, male)

Ex: el más viejo

"El menos" + adjective (singular, male)

Ex: el menos inteligente

Singular female subject:

"La más" + adjective (singular, female)

Ex: la más linda

"La menos" + adjective (singular, female)

Ex: la menos sociable

Plural male subject:

"Los más" + adjective (plural, male)

Ex: los más tímidos

"Las menos" + adjective (plural, male)

Ex: los menos aburridos

Plural female subject:

"Las más" + adjective (plural, female)

Ex: las más divertidas

"Las menos" + adjective (plural, female)

Ex: las menos simpáticas

corras is the only one that is informal but doesn't follow the suffix rule. correr is the verb. corre is the formal verb form. corra would be used as the formal is corre ended with an a.

your best bet would be corras, it's the only one that is informal but is still wrong