After 40 minutes, Ralph has already painted (40/60)/12=1/18 of the fence
Lisa's speed is 1/15 fence/hour, Ralph's speed is 1/12 fence/hour, hence when they help each other their combined speed is 1/15+1/12=3/20
Thus we need to solve 3/20*x=17/18 thus x=170/27 hours (approx 6 hours 15 mins)
Answer: b.
Step-by-step explanation:
Based on the information given, you can write the following expression:

Where k is the the constant of variation
If y=4/63 when x=3, then you can substitute these values into the expression and solve for k:

Substitute k into the expression. Then the equation is:

Substitute x=5 into the equation. Then, y is:

Step-by-step explanation:
3x+18=4x+2
x= 16
measure of <A = 66°