Answer: 10 tulips, 10 lilies and 23 roses.
Step-by-step explanation:
Let's define the variables:
T = number of tulips that Jennifer bought
L = number of lilies that Jennifer bought
R = number of roses that Jennifer bought
Each tulip costs $0.18
Each lily costs $0.27
Each rose costs $0.55
We know that:
"She bought the same number of tulips as lilies."
T = L
" She bought three more roses than tulips and lilies combined."
R = T + L + 3
"she paid $17.15 in all"
T*$0.18 + L*$0.27 + R*$0.55 = $17.15
Then we have a system of 3 equations:
T = L
R = T + L + 3
T*$0.18 + L*$0.27 + R*$0.55 = $17.15
The first step to solve this is to replace the first equation into the other two, and get:
R = 2*L + 3
L*$0.18 + L*$0.27 + R*$0.55 = $17.15
Now we can replace the first equation into the second:
L*$0.18 + L*$0.27 + (2*L + 3)*$0.55 = $17.15
Now we can solve this for L.
L*($0.18 + $0.27 + 2*$0.55) + 3*$0.55 = $17.15
L*$1.55 + $1.66 = $17.15
L*$1.55 = $17.15 - $1.66 = $15.50
L = $15.50/$1.55 = 10
Then Jennifer bought 10 lilies.
And by the other two equations:
T = L = 10
She bought 10 tulips.
R = L + T + 3 = 10 + 10 + 3 = 23
She bought 23 roses
