Answer:
a) 3 people will need 35 days to paint the bridge
b) p=105/t
Step-by-step explanation:
a)
We have 7 people each one is to work 15 days, so the bridge needs a total of 7(15) days of work
7(15)=105
Then we have 3 people each one is to work t days, altogether should do a total of 105 days of work
3(t)=105
Solve for t
t=35
b)
Substitute p for 3 in the second equation
p(t)=105
Solve for p
p=105/t