Weight of the Spices

Four of the 11 spices used in making incense for the temple were stacte, onycha, galbanum and frankincense. (Shemos 30:34)  We are told that equal amounts of each are to be used in making the incense.

Question: If the combined weight of these 4 spices is 160 maneh, how much stacte would we use?

Answer:  160/4 = 40 maneh.