Answer:
Explanation:
We are going to make a questioning. Look:
If in 3 minutes she can type 120 word
In 1 min how many will she type X
We adopt X as a thing witch we don't know. This forms a Rule of three. It happens when we have got 3 values but miss us 1 yet.
Generraly you'll sort the values by type. In this case, I put minutes under minute and words under words.
A Fast way to solve is: multiply where there is not an incognt (1*120) and divide by what left (3)
So:
1*120=120
Divided by 3 (120/3) it's equals 40 words per minute.
Good studies!
-ZehTheJohn