Sкруга = пR^2
R1 = 1/2D = 1/2 * 18 = 9 cм
S1= 3.14*( 9*9)= 254,34 см2
R2= 1/2*3= 1,5 см
S2= 3.14* (1,5*1,5)= 7,065 см2
254,34 : 7,065 = 1 : 36
1) 2/3; 4/5;1;5/4
2)1;1/6;1/7;1/8
3/8+2/9+1/6=27/72+16/72+12/72=55/72
1-55/72= 72/72-55/72=17/72 -4 верстальщик