Answer:
10
Step-by-step explanation:
Given that:
Company A:
40 defective out of every 5000
Company B :
30 out of every 6000
To obtain the highest number of defective phones both companies can produce in common :
Factors of :
40 : 2, 4, 5, 8, 10, 20, 40
30 : 2, 3, 5, 6, 10, 15, 30
Hence, highest number of defective phones both companies can produce in common is 10