Answer:
12) 141.75g
13) 150g
14) 12kg
Explanation:
By using common sense.
None of the weights can be negative, so that rules out the first option for both questions 12/13.
12) For question 12 that leaves you with two answers. You have to decide between a book weighing 141.75g or 141.75kg.
Considering that books are fairly light, and 141.75kg is quite a hefty weight, I would chose 141.75g.
13) Same again for question 13. If you have a 150kg smart phone, I'd be very surprised that you could hold it.
14) Options 1/2 are very inappropriate for a weight of 24 bottles of water.