Verified Answer :

To be clear I understand:
Dorothy types 120 words per minute.

let's say that her rate per minute = x

x1 =120//divide by 1:
x=120

for 1.75 we have the following equation:
x
1.75=y

where we have to find y.

we know that x=120
so we have:

1201.75=y
120
(1+0.75)=y// (0.75 of 120 is 90. We can find it by diving 120 by 4 (30) and multiplying by 3 (3*30=90)).
120+90=y
210=y

so she can type 210 words per 1.75 minutes.

Let me know if youy have further questions!

She typed 210 words in that time frame