Question

90% от 20% числа b равны 9,9. Найди число b.

Answer 1

(b*20/100)*90/100=9.9
b*20/100=9.9*100/90
b*20/100=11
b=11*100/20
b=55

Answer 2

cпс

Answer 3

90%-9.9

100%-х

х= 100*9.9:90=11

11-20%

x-100%

x=100*11:20=55

Answer 4

спс