Question

A bag holds 1 blue block and 3 yellow blocks. How many green blocks should be added to the bag to make the probability of randomly selecting a green block from the bag equal to 1/2 ?

Answer 1

Answer:

Step-by-step explanation:

ITS 4

Answer 2

$n$ - the number of green blocks which is equal to the number of favourable events
$1+3+n=4n$ - the number of all blocks, which is equal to the number of all possible outcomes

$P(A)=\dfrac{n}{4+n}=\dfrac{1}{2}\\ 1\cdot( 4+n)=2\cdot n\\ 4+n=2n\\ 2n-n=4\\ n=4$