Probability: Two Independent Events

There are two students in Mr. Jones' English class. Each of these students usually get a $D$ ($60-69$%) on their weekly spelling tests. Mr. Jones announces that next week's spelling test will be taken in pairs. If each of these $D$ students independently has a $69$% chance of knowing how to spell each word correctly and knows which words they can and cannot spell (no one will guess how to spell a word they do not know how to spell for sure), what grade will they earn if they collaborate on that spelling test?