Question

Intr-o urna sunt bile albe , rosii si negre . cele albe reprezinta 30 % din total , cele rosii 20 % din numarul celor albe , iar cele negre 32 . aflati :

Answer 1

S - nr total de bile

30% din S=  30/100 * S=  3/10 * S=  3S/10 -bile albe

20% din 3S/10=  20/100 * 3S/10=  1/5 * 3S/10=   3S/50 -bile rosii

3S/10 +3S/50 +32 =S   aducem la acelasi numitor

15S +3S + 1600=50S

32S = 1600


S=50 bile albe, rosii, negre

3S/10 -bile albe   ( 3×50)/10=15 bile albe

3S/50 -bile rosii  ( 3×50)/50=  3 bile rosii