6. Probability of finding defective phone=4/60=1/15
No. of phones=4200
No. of phones likely to be defective=4200/15=280
7. Probability of an elk being infected=8/50=4/25 
No. of elks=4500
No. of elks likely to be infected= (4*4500)/25
 = 4*180
 =720
Hope it helped:)