Question

dau coroana, cat de repede se poate

Answer 1

Răspuns:

a=60 ; b=140 ; c=220

Explicație pas cu pas:

a, b, c d.p. cu 3, 7, 11

$\frac{a}{3} = \frac{b}{7} = \frac{c}{11} = k$

a/3=k => a=3k

b/7=k => b=7k

c/11=k => c=11k

a+b+c=420 => 3k+7k+11k=420

21k=420 => k=420:21=20

a=3k=3×20=60

b=7k=7×20=140

c=11k=11×20=220