In a test (+5) marks are given for every correct answer and (-2) marks are given for every incorrect answer. Radhika answered all the questions and scored 30 marks though she got 10 correct answers. How many incorrect answers had they attempted?

10 incorrect answers

Step-by-step explanation:

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.

ending amount = beginning amount / (2^n)

where "n" = number of half-lives (or elapsed time / half-life)

ending amount = 50 mg / (2 ^10 / 5.3)

ending amount = 50 mg / (2 ^ 1.8867924528)

ending amount = 50 m / 3.6981210597

ending amount = 13.5203794557 mg

or about 13.5 mg remain

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