Question

Giselle works as a carpenter and as a blacksmith. She earns $20\$20$20dollar sign, 20 per hour as a carpenter and $25\$25$25dollar sign, 25 per hour as a blacksmith. Last week, Giselle worked both jobs for a total of 30303030 hours, and earned a total of $690\$690$690dollar sign, 690. How long did Giselle work as a carpenter last week, and how long did she work as a blacksmith?

Answer 1

let x be carpenter hours n y be blacksmith hours
total work 30 hrs = x + y
total earning $690 = 20x + 25y
from first eqn, x = 30 - y
substitute in second eqn
690 = 20(30-y) + 25y
690 = 600 - 20y + 25y
690 - 600 = -20y + 25y
90 = 5y
y = 18 hours
x = 30 - y = 30 - 18 = 12 hours

Answer 2

She worked 40 hours last week and worked 45 hours as a Black smith