6. If \( 20 \% \) of the Candidates faited, i. how many faited? ii. What is the least mark a Candidate should seane in ordor to pass. 2. The perimetor of a reaction plat of land whose length is \( (2 x+5) \mathrm{m} \) and width \( (x-10) \mathrm{m} \) is 80 m . Find the value of \( x \). solution

To find out how many candidates failed, you first need to know the total number of candidates. If, for example, there were 100 candidates, then \( 20\% \) failed means \( 20\% \times 100 = 20 \) candidates failed. As for the least mark needed to pass, this typically depends on the total possible marks. For a passing score of, say, 40 out of 100, then a candidate would need at least 40 marks to pass. Now, for the perimeter of the rectangular plot of land, you use the formula for the perimeter \( P = 2(\text{length} + \text{width}) \). Plugging in the given dimensions, we have \( 80 = 2((2x + 5) + (x - 10)) \). Simplifying this gives \( 80 = 2(3x - 5) \) or \( 40 = 3x - 5 \). Re-arranging gives \( 3x = 45 \) or \( x = 15 \). So, the value of \( x \) is \( 15 \).