Question

Can someone help me with this question?

Answer 1

so, she can type 50 words in 1 minute, well, 1 minute is 60 seconds, so she really can type 50 words in 60 seconds, hmmmm how many seconds does it take her for 1 word?


`\bf \begin{array}{ccll} words&seconds\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ 50&60\\ 1&s \end{array}\implies \cfrac{50}{1}=\cfrac{60}{s}\implies s=\cfrac{1\cdot 60}{50}\implies s=\cfrac{6}{5}`

so, we know that 1 Jiffy is 1/100 of a second, so, how many Jiffies are there in 6/5 of a second then?


`\bf \begin{array}{ccll} jiffies&seconds\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ 1&(1)/(100)\\\\ j&(6)/(5) \end{array}\implies \cfrac{1}{j}=\cfrac{\quad (1)/(100)\quad }{(6)/(5)}\implies \cfrac{1}{j}=\cfrac{1}{100}\cdot \cfrac{5}{6} \\\\\\ \cfrac{1}{j}=\cfrac{5}{600}\implies \cfrac{1\cdot 600}{5}=j\implies 120=j`