Question

Calcule: a)25% de 304 ml b)80% de 15 litros

Answer 1

a) 304*25/100 = 76 ml
b) 15* 80/100 = 12 litros

Answer 2

a)25% de 304 ml
304 ml ----- 100%  ⇒  100x=304·25 ⇒ 100x=7600 ⇒ x=7600/100 ⇒ x=76 ml
  x  ----------  25% 

b) 80% de 15 litros
15 l ------- 100% ⇒ 100x=15·80 ⇒ 100x=1200 ⇒ x=1200/100 ⇒ x=12 litros
  x  --------  80%