Mathematics
mitikeeiler:

Suppose two drugs are routinely used for the treatment of thyroid dysfunction. Drug X is known to cure the disorder 75% of the time and costs $88. Drug Y is known to cure the disorder 60% of the time and costs$75. The two drugs work independent of each other. The two treatment plans are as follows: Plan A: Treatment with Drug X—if not effective, treatment with Drug Y Plan B: Treatment with Drug Y—if not effective, treatment with Drug X 1 Select the correct answer. For what part of the population is Plan B NOT effective? A. 40% B. 30% C. 15% D. 10%

Hoodmemes:

Alright I'd say u wanna focus on these parts 'Drug X is known to cure the disorder 75% of the time and costs $88. " and "Plan A: Treatment with Drug X—if not effective, treatment with Drug Y" Now drug (X) could be non-effective with drug Y So i'd say there is a 1% chance that it won't work with drug Y. (U need to be keeping the percentage (1) the same) U now wanna (Divide) (75%) by (100) $75\div100=0.75$ Now (Subtract) (0.75) from (1) $1-0.75=0.25$ Lets Focus on these parts now "Drug Y is known to cure the disorder 60% of the time and costs$75." and "Plan B: Treatment with Drug Y—if not effective, treatment with Drug X" Drug (Y) could be non-effective with drug X So as said before there is a (1%) chance that it won't work with drug X (U can keep the (1) the same) U know wanna (Divide) (60%) by (100) $60\div100=0.6$ Now (Subtract) (0.6) from (1) $1-0.6=0.4$ Now u wanna (Multiply) (0.25) by (0.4) $0.25\times0.4=0.1$ U know wanna (Multiply) (0.1) by (100) $0.1\times100=10$ So answer option D.)10% would be correct.