Question

If 1.2 kilograms of rust form on a bridge in five days, what should be the rate of reaction in grams per hour? (Recall that a bar over the number means that zero is significant.)

Answer 1

1.2 KG = 1200 gram
1200 gram per 5 days
5 days = 5*24=120 hours

so 1200 grams or rust in 120 hours
how many gram is that per hour?

Answer 2

10g/hr?

Answer 3

6 g/hr

Answer 4

eee i made a mistake :P
\(\large\dfrac{1200}{120}=10~g/hr\)

you were right :)