Question

elena has a total of 70 pencils, where there are 2 mechanical pencils for every 5 wooden pencils. how many mechanical pencils are in the box?

Explanation:

Step1: Find the total parts in the ratio

The ratio of mechanical pencils to wooden pencils is \(2:5\). So the total number of parts is \(2 + 5=7\) parts.

Step2: Find the value of one part

Elena has a total of 70 pencils. Since there are 7 parts in total, the value of one part is \(\frac{70}{7} = 10\) pencils per part.

Step3: Find the number of mechanical pencils

Mechanical pencils are 2 parts. So the number of mechanical pencils is \(2\times10 = 20\).

Answer:

20