Question

Саше на марафоне предложили 20 задач. За верно решенную задачу ставят 8 баллов, за неверно решенную задачу - минус 5 баллов, за задачу которую не решал -0 Саше в сумме набрал 13 баллов.

Answer 1

8*6-5*7=13
6-решил
7-неверно
всего 13 задач

Answer 2

Calculation of Sasha's Score

To calculate Sasha's score, we need to consider the points awarded for each correctly solved problem, the points deducted for each incorrectly solved problem, and the points for problems that Sasha did not attempt.

According to the given information: - Each correctly solved problem is awarded 8 points. - Each incorrectly solved problem is deducted 5 points. - For problems that Sasha did not attempt, no points are awarded or deducted.

Sasha's total score is given as 13 points.

Let's break down the calculation based on the information provided:

1. Let's assume Sasha solved x problems correctly. - The points awarded for correctly solved problems: 8x.

2. Sasha also solved 20 - x problems incorrectly. - The points deducted for incorrectly solved problems: -5(20 - x).

3. Sasha did not attempt 20 - (x + (20 - x)) = 0 problems. - No points are awarded or deducted for problems not attempted.

Based on the given information, Sasha's total score is 13 points. We can set up the equation:

8x - 5(20 - x) = 13

Solving this equation will give us the number of problems Sasha solved correctly.

Let's solve the equation:

8x - 5(20 - x) = 13

8x - 100 + 5x = 13

13x - 100 = 13

13x = 113

x = 113 / 13

x ≈ 8.69

Since the number of problems solved must be a whole number, we can round down to the nearest whole number.

Therefore, Sasha solved approximately 8 problems correctly.

Conclusion

Based on the given information, Sasha solved approximately 8 problems correctly out of the 20 problems offered in the marathon.