Makayla Reilly
2022-09-14
Answered

I scored a mean of 80 marks for 3 tests, scoring 20 marks more for Science than Maths and 5 marks less for History than Maths. What was the score on the Maths test?

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illpnthr21vw

Answered 2022-09-15
Author has **17** answers

Let marks scored in maths = n

Marks scored in science = n+20

Marks scored in History = n-5

According to question:

$$\Rightarrow \frac{n+(n+20)+(n-5)}{3}=80\phantom{\rule{0ex}{0ex}}\Rightarrow n+n+20+n-5=80\times 3\phantom{\rule{0ex}{0ex}}3n+15=240\phantom{\rule{0ex}{0ex}}3n-240-15\phantom{\rule{0ex}{0ex}}3n=225\phantom{\rule{0ex}{0ex}}n=\frac{225}{3}\phantom{\rule{0ex}{0ex}}n=75$$

Score of Maths Test = 75 marks.

Marks scored in science = n+20

Marks scored in History = n-5

According to question:

$$\Rightarrow \frac{n+(n+20)+(n-5)}{3}=80\phantom{\rule{0ex}{0ex}}\Rightarrow n+n+20+n-5=80\times 3\phantom{\rule{0ex}{0ex}}3n+15=240\phantom{\rule{0ex}{0ex}}3n-240-15\phantom{\rule{0ex}{0ex}}3n=225\phantom{\rule{0ex}{0ex}}n=\frac{225}{3}\phantom{\rule{0ex}{0ex}}n=75$$

Score of Maths Test = 75 marks.

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