It would take Steve 4 hours to paint a room. If Andre helps him, they can finish painting the room in 3 hours. How long would Andre take to paint the room by himself?

12 hours

Step-by-step explanation:

Given data

Steve= 4 hours

Steve and Andrea= 3 hours

Applying the combined work formula

1/A+1/B= 1/T

1/4+1/B= 1/3

solve for B

B+4/4B= 1/3

cross multiply

3(B+4)= 4B

3B+12= 4B

12= 4B-3B

12= B

Hence Andrea will spend 12 hours alone

d. bc = 12 and ef = 16

step-by-step explanation:

we are given that δabc : δdef such that .

also, it is given that

so, from the options, we need that .

a.

b.

c.  

d.

as, we can see that only option d gives the same ratio as i.e. .

hence, the possible lengths are bc = 12 and ef = 16.

1.true 2.false? ? i think. .

step-by-step explanation: