Janet's math test consists of 20 problems. For every correctly solved problem,sherecieves 8 points. For every inccorectly solved problem, she subtracts 5 points.For every problem that she skips, she recieves 0 points. Janet earned 13 points onthe test. How many problems did Janet try and solve? Explain​

Answer:8 correct, 6 wrong : 14 problems tried!Step-by-step explanation:If she gets 8 points by every question correctly answered and she got 13 points in total, she must have answered at least two questions (if she answers only 1 she gets at maximum 8 points, not reaching 13 never). So lets try to find the solution.If she answered 2 and mistaken 1 she would get: 2*8 - 1*5 = 16 - 5 = 11 -> So this is not correct.If she answered 3 correct she would get 24 points, with 2 mistaken  answers she would have: 8*3 - 5*2 = 24 -10 = 14 We need to see something important in this patterns:As the wrong questions always subtract a multiple of 5, and we need a result of 13, we CAN'T have an even number of wrong questions, because this would imply a subtract of numbers like 10, 20, 30, etc; and as the correct answers only give us even numbers (8, 16, 32, 64, etc), the result of subtracting 2 even numbers would never be 13. And as we will be subtracting a number with a 5 in the units, the points for correct answers MUST have an 8 in the units, as 8-5=13.So, lets go to the first posible number that ends in 8 and is multiple of 8 and greater than 16. This is 48. 48 = 6*8, this is, lets think about 6 correct answers that sum 48 points. We now need to subtract a number to 48 that gives us 13. Which is?48 - x = 13 <----> x = 35So, we need a number of incorrect answers that sum 35. As every wrong answer sums 5 points, we need 7 wring answers (7*5 = 35):8*6 - 5*7 = 48 - 35 = 13 points!! There were 14 problems tried to solve