Question

Suyash scored 10 marks more in second test than that in the first. 5 times the score of the second test is the same as square of the score in the first test. Find his score in the first test.

Answer 1

Let the score in the first test be x. 
Suyash's score in second test is 10 more than that in the first. 
So, his score in the second test = x + 10
5 times the score of the second test is the same as square of the score in the first test. 

\[5\left( x + 10 \right) = x^2 \]
\[ \Rightarrow 5x + 50 = x^2 \]
\[ \Rightarrow x^2 - 5x - 50 = 0\]
\[ \Rightarrow x^2 - 10x + 5x - 50 = 0\]
\[ \Rightarrow x\left( x - 10 \right) + 5\left( x - 10 \right) = 0\]
\[ \Rightarrow \left( x + 5 \right)\left( x - 10 \right) = 0\]
\[ \Rightarrow x = 10, - 5\] 

The score is not negative so, Suyash scored 10 marks in first test.