Question

in a sample of mice in dr. rices laboratory, 15% of mice have a nonsense mutation on their egfr gene and 10% of mice have a missense mutation on their egfr gene (none of the mice have both mutations). if there are 200 mice in the sample, how many do not have either a nonsense or missense mutation on their egfr gene?
a) 75 mice
b) 120 mice
c) 150 mice
d) 175 mice

Explanation:

Step1: Calculate the percentage of mice with mutations

The percentage of mice with a nonsense mutation is 15% and with a missense mutation is 10%. Since none of the mice have both mutations, the percentage of mice with either mutation is $15\%+ 10\%=25\%$.

Step2: Calculate the percentage of mice without mutations

The percentage of mice without either mutation is $100\% - 25\%=75\%$.

Step3: Calculate the number of mice without mutations

There are 200 mice in the sample. So the number of mice without either mutation is $200\times0.75 = 150$.

Answer:

C. 150 mice