(i) Marks given for one correct answer = 3
Marks given for 12 correct answers = 3 x 12 = 36
Radhika scored 20 marks.
Therefore, Marks obtained for incorrect answers = 20 – 36 = –16
Now, marks given for one incorrect answer = –2
Therefore, number of incorrect answers = (-16) ÷ (-2) = 8
Thus, Radhika has attempted 8 incorrect questions.
(ii) Marks given for seven correct answers = 3 x 7 = 21
Mohini scores = –5
Marks obtained for incorrect answers = = –5 – 21 = –26
Now, marks given for one incorrect answer = –2
Therefore, number of incorrect answers =(-26) ÷ (-2) = 13
Thus, Mohini has attempted 13 incorrect questions.
Write equations for the following statements:
(i) The sum of numbers x and 4 is 9.
(ii) 2 subtracted from y is 8.
(iii) Ten times a is 70.
(iv) The number b divided by 5 gives 6.
(v) Three-fourth of t is 15.
(vi) Seven times m plus 7 gets you 77.
(vii) One-fourth of a number x minus 4 gives 4.
(viii) If you take away 6 from 6 times y, you get 60.
(ix) If you add 3 to one-third of z, you get 30