Line-producing 6197

The new line-producing screws did not work at total capacity from the beginning. On Monday, she produced 20% of the daily norm. On Tuesday, she already met 4/5 of the daily norm. By what percentage was the number of screws made on Tuesday higher than on Monday?

Correct answer:

p =  300 %

Step-by-step explanation:

$$\begin{gathered} a=0.20 \\ b=4/5=\frac{4}{5}=0.8 \\ p=100\cdot \frac{b-a}{a}=100\cdot \frac{0.8-0.2}{0.2}=300=300\% \\ n=1000 \\ {n}_1=a\cdot n=0.2\cdot 1000=200 \\ {n}_2=b\cdot n=\frac{4}{5}\cdot 1000=\frac{4\cdot 1000}{5}=\frac{4000}{5}=800 \\ {p}_2=100\cdot \frac{n_2-n_1}{n_1}=100\cdot \frac{800-200}{200}=300\% \end{gathered}$$

Try another example