Sharita does a special typing job for scientist she charges 7 dollars for the first 3 and 3 dollars for each additonal page of scientist typing , sonia , a biologist , paid 100 dollars to have a research paper typed how many pages long was sonias paper

Let's just work through this one using logic.  Here's what we know:* it costs $7 for first 3 pages* it costs $3 for each additional page* $100 total was spent$100 - $7 leaves us with $93 remaining.  Divide that $93 by $3 to get 31 pages.  Add that 31 pages to the initial 3 you spent $7 on and get a total of 34 pages for $100.