SOLUTION: A consulting engineer's time is billed at $100 per hour, and her assistant's is billed at $20 per hour. A customer received a bill for $1200 for a certain job. If the assistant wor

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A consulting engineer's time is billed at $100 per hour, and her assistant's is billed at $20 per hour. A customer received a bill for $1200 for a certain job. If the assistant wor      Log On


   

Question 121396This question is from textbook algebra and trigonometry with analiytic geometry
: A consulting engineer's time is billed at $100 per hour, and her assistant's is billed at $20 per hour. A customer received a bill for $1200 for a certain job. If the assistant worked 3 hours less than the engineer, how much time did each bill on the job? This question is from textbook algebra and trigonometry with analiytic geometry

Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
100X+20(X-3)=1200
100X+20X-60=1200
120X=1200+60
120X=1260
X=1260/120
X=10.5 HOURS WAS BILLED FOR THE ENGINEER OR:
100*10.5=$1050 WAS THE ENGINEER'S BILL.
20(10.5-3)=20*7.5=$150 WAS THE ASSISTANT'S BILL.
PROOF
100*10.5+20*7.5=1200
1050+150=1200
1200=1200