At a cafeteria, Mary orders two pieces of toast and a bagel, which comes out to 3.15. Gary orders a bagel and four muffins, which comes out to 7.85. Larry orders a piece of toast, two bagels, and three muffins, which comes out to 9.75. How many cents does one bagel cost?
At a cafeteria, Mary orders two pieces of toast and a bagel, which comes out to 3.15. Gary orders a bagel and four muffins, which comes out to 7.85. Larry orders a piece of toast, two bagels, and three muffins, which comes out to 9.75. How many cents does one bagel cost?
wiseowl, what's up with the about a million postings? Is this your homework or what?
T is for toast
B is for bagel
M is for muffin
2T + B = 315 (I'm using cents because the answer will be in cents.)
B + 4M = 785
T + 2B + 3M = 975
from 1st equation 2T = (315 – B) so T = (315 – B) / 2
from 2nd equation 4M = (785 – B) so M = (785 – B) / 4
Now we have T and M in terms of B so substitute it into the 3rd equation.
(315 – B) 2B 3 • (785 – B)
–––––––– + –––– + –––––––––– = 975
2 1 4
Let's get rid of those denominators by multiplying both sides times 4.
2 • (315 – B) + 4 • 2B + 1 • 3 • (785 – B) = 4 • 975
Multiply it out (630 – 2B) + 8B + (2355 – 3B) = 3900
Combine like terms 3B = 915
B = 305 ...... One bagel costs 305 ¢
Plugging into original equations, a toast costs 5¢ and a muffin costs 120¢
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