Răspuns:
bile rosii : 3/6
bile albe : 5/8 din rest
bile negre : 9
_____________
? bile in cutie
/____ /____ /____ /____ /____ /____ / 6/6
rosii
/_ /_ /_ /_ /_ /_ /_ /_ / rest
albe
/_ /_ /_ / 9
Explicație pas cu pas: negre
9÷3×5= 3×5= 15 bile albe
3×8=24 rest
24×2 = 48 bile in cutie