Question

A bag contains a number of marbles of which $80$ are red, $24$ are white and the rest are blue. If the probability of randomly selecting a blue marble from this bag is $\frac{1}{5}$, how many blue marbles are there in the bag?

• A. $25$
• B. $26$
• C. $27$
• D. $28$

Answer 1

The correct option is B $26$

A bag contains a number of marbles of which 80 are red, 24 are white and the rest are blue. If the probability of randomly selecting a blue marble from this bag is $\frac{1}{5}$

The Probabaility of red marble is $P\left(E\right)=\frac{1}{5}=$$\frac{blue}{red+blue+white}$$\frac{blue}{80+24+blue}$

from Above we get

$4$ blue $=104$

blue $=26$