Choose a variable to represent one of the unknowns. Express the remaining unknowns in terms of the variable you chose in step 1.
Look for a relationship between the unknowns given in the problem. Write an equation. (Look for the other relationship given in the problem.) Two sides of a triangle are equal in length and double the length of the shortest side. The perimeter of the triangle is 35 inches.
From the information given, you can say that 5 marks for the number of correct answers minus two marks for the number of incorrect answers is equal to 30 that is the score that Radhika got:
(5*10)-2x= 30, where x is the number of incorrect answers.
Now, you can solve for x:
50-2x=30
50-30=2x
20=2x
x=20/2
x=10
According to this, the answer is that they attempted 10 incorrect answers.