5 yrs

5 years ago, the average age of Rasmi and Suravi was 20 years. Now, the average age of Rasmi, Suravi, and Mita is 30 years. What will be the age of Mita after 15 years?

Final Answer:

x =  55

Step-by-step explanation:

$$\begin{gathered} \frac{r-5+s-5}{2}=20 \\ \frac{r+s+m}{3}=30 \\ r+s-10=2\cdot 20 \\ r+s=50 \\ \frac{r+s+m}{3}=30 \\ \frac{50+m}{3}=30 \\ 50+m=30\cdot 3 \\ m=90-50=40 \\ x=m+15=40+15=55 \end{gathered}$$

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