Katie hit four more home runs than three times the number of home runs hit by Kristen. Together they hit 20 home runs. How many home runs did Kristen hit?
Let Ka = no of home runs hit by Katie
Let Kr = no of home runs hit by Kristen
Then,
Ka = 4 + 3*Kr (Katie hit four more home runs than three times the number of home runs hit by Kristen)
Ka + Kr = 20 (Together they hit 20 home runs)
Substituting for Ka = 4 + 3*Kr into the 2nd eqn above,
4 + 3*Kr + Kr = 20
4 + 4*Kr = 20
4*Kr = 16
Kr = 4. Therefore Ka = 16
Answer: Katie hit 16 home runs. Kristen hit 4 home runs