Question

Sergio has decided to weigh his reference books. His largest encyclopedia weighs 7.49 pounds, and his largest dictionary weighs 3.91 kilograms. If one pound is equal to 0.4535924 kilograms, which book is heavier, and how many more kilograms does it weigh than the other?
a.
The encyclopedia weighs 1.61 kg more than the dictionary.
b.
The encyclopedia weighs 0.87 kg more than the dictionary.
c.
The dictionary weighs 1.13 kg more than the encyclopedia.
d.
The dictionary weighs 0.51 kg more than the encyclopedia.

Answer 1

Convert the encyclopedia to kilograms: 7.49 lb × 0.4535924 kg/lb = 3.397407076 kg (≈ 3.3974 kg).
Compare to the dictionary: 3.91 kg − 3.397407076 kg = 0.512592924 kg ≈ 0.51 kg.

So the dictionary is heavier by about 0.51 kg. Answer: d.