In a certain month a base ball team that played 60 games had won 30% of its games played. After a phenomenal winning streak this team raised its average to 50%. How many games must the team have won in a row to attain this average ?

A. 12

B. 20

C. 24

D. 30

Answer: Option C

Solution(By Examveda Team)

Number of games already won
= 30% of 60
= 18
Let the required number of games be $$x$$
Then,
$$\eqalign{ & \Rightarrow \frac{{18 + x}}{{60 + x}} \times 100 = 50 \cr & \Rightarrow \frac{{18 + x}}{{60 + x}} = \frac{1}{2} \cr & \Rightarrow 36 + 2x = 60 + x \cr & \Rightarrow x = 24 \cr} $$