Answer:
18 oz of nuts were there.
Explanation:
Given:
Total quantity of trail mix = 42 oz.
Ratio of fruit to nuts are 4:3.
Now, to find oz of nuts:
Let the quantity of fruits be

And the quantity of nuts be

As given, the total quantity of trail mix = 42 oz.
According to question:

⇒

Dividing both sides by 42 we get:
⇒

Now, to get the quantity of nuts we put the value of
:
Quantity of fruits

Therefore, 18 oz of nuts were there.