10th Class
Mathematics
Probability
Question Bank
Probability
question_answer
A box contains 60 pens which are blue-inked or black-inked. If a pen is picked at random, the probability of picking a blue-inked pen is \[\frac{2}{5}\], what is the number of blue-inked pens in the box?
A) 32
B) 48
C) 30
D) 24
Correct Answer:
D
Solution :
(d): Let BLUE pens be ?a? P (blue) \[=\frac{a}{60}=\frac{2}{5}\Rightarrow a=24\]