Answer:
Hence, the percent decrease is:
25%
Step-by-step explanation:
It is given that:
Misha's test score decreased from 80% to 60%.
We know that the percent increase or decrease in the test score is given as:
\(Percent\ decrease=\dfrac{New\ score-Old \ score}{Old \ score}\times 100\)
Let the total score be'x'.
Hence,
\(old\ score=\dfrac{80}{100}\times x\\\\old\ score=0.8x\)
similarly new score is:
\(New\ score=0.6x\)
Hence,
\(Percent\ decrease=\dfrac{0.8x-0.6x}{0.8x}\times 100\\\\=\dfrac{0.2x}{0.8x}\times 100\\\\=\dfrac{2}{8}\times 100\\\\=25\%\)
Hence, the percent decrease is:
25%
