I’m pretty sure the answer is d or c
Your equation is 6/25 = d/30. to solve this equation we have to get d by itself! to do this, you have to multiply each side by 30 since d is being divided by thirty. d/30 x 30 = d, 6/25 x 30 = 7.2, or 7 2/10
therefore, d = 7.2
hope this helps!
The infinitive phrase in the sentence is 'to learn new ideas from his experiments' since it has the (to + simple form of the verb + modifers). Its function is a noun because it is the direct object for the verb 'tried'.
