Keep 6/15 the same and change Division sign into a multiplication sign and flip 4/21 and that will become 21/4. \(\frac{6}{15}* \frac{21}{4}= \frac{126}{60}\) 126/60=21/10 and 21/10 as a mixed number is 2 1/10 so your answer is 2 1/10. Hoped I helped. :)
