Question

Richardson sat for a math Olympics exam that had 25 questions for every question he got right he earn 10 points in for every question he got wrong he lost 2.5. Five points he answered every question and got a score of 150 how many questions did he get right

Answer 1

Therefore he got 17 questions right.

Step-by-step explanation:

Given Richardson sat for a math Olympic exam that had 25 questions for every right question he earn 10 points and for every wrong he lost 2.5 points.

Let , he got x questions right  .

Number of wrong question is (25-x)

According to the problem,

$x\times 10 -(25-x)2.5 = 150$

$\Leftrightarrow 10x -62.5+2.5x = 150$

$\Leftrightarrow 12.5 x = 150 +62.5$

$\Leftrightarrow 12.5 x = 212.5$

$\Leftrightarrow x =\frac{ 212.5}{12.5}$

$\Leftrightarrow x = 17$

Therefore he got 17 questions right.