Answer:
90b grams.
Step-by-step explanation:
Given that,
Weight of a box = 90 grams
We need to find the weight of b boxes.
For this, we can use unitary method. The weight of one box is given then we can find the weight of many boxes.
i.e.
Weight of b boxes = 90×b
= 90b grams
Hence, the weight of b boxes is 90b grams.
