Răspuns:
Explicație pas cu pas:
2.
(120/300) x 100 = 40%
3.
48 elevi
20 fete
48 - 20 = 28 baieti
(28/48) x 100 = 58,(3)%
4.
a/b = 2/5
a = 2b/5 = 40b/100 = b*40%
b = 5a/2 = 250a/100 = a*250%
a + b = a + 5a/2 = 2a/2 + 5a/2 = 7a/2 = 350a/100 = a*350%
b - a = b - 2b/5 = 5b/5 - 2b/5 = 3b/5 = 60b/100 = b*60%
