CLASS 7
1.
In a test, +4 marks are given for every
correct answer and -1 mark are given for
every incorrect answer.
i) Ravi attempted all the questions and scored
+30 marks though he got 10 correct answers.
How many incorrect answers has she
attempted?
ii) Sameera scored – 12 marks. She got 16
incorrect answers. How many correct
answers has she attempted?
Explanation:
1 / For every correct answer,
mark is +4
for 10 correct answer,
mark is 10×(+4) = +40
but his mark is +30
so , (40 – 30 ) = 10
So, -1 is for 1 incorrect answer
-10 is for (-10)÷(-1) = 10
So , Ravi attempted 10 incorrect answer.
if you try the reverse you will get the second answer too.
Answer:
(I) ravi attempt 2 incorrect answer
here 8*4=32 and 2 are incorrect so 32-2=30
(ii) 1 correct answer
Explanation:
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