S=U*T
S1=S2=1/2s
U1*T1=U2*T2
U2=(U1*T1)/T2=48/5
Ответ : В комнате : 10 - 2 = 8 стульев ,
A) 3/5 + 7/25 + 1/15 = 45/75 + 21/75 +5/75 = 66/75 + 5/75 = 71/75
Б) 13/51 +1/3 + 2/17 = 13/51 +17/51 + 6/51= 36/51 = 12/17
В) 3/7 + 2/5 +4/7 + 3/5 = 7/7 + 5/5 = 1+1=2
Г) 11/17 + 18/24 + 1/4 + 6/17 = 17/17 + 18/24 + 6/24 = 17/17 + 24/24 = 1+1=2