Answer:
the second one, ((6 x 5) x 4) +((5 x 4) x 2) = 160
the third one, ((7 x 6) x 4) + (6 x 4) x 2) = 216
the fourth one, ((8 x 4) x 4) + ((4 x 3) x 2) = 152
Step-by-step explanation:
3 pipes take 12 hours
⇒ In 1 hour, the 3 pipes can fill 1/12 of the pool
2 of the pipes take 18 hours
⇒ in 1 hour, the 2 pipes can fill 1/18 of the pool
In 1 hour, the third pipe alone can fill :

Time needed :

----------------------------------------------------------------------------------------
Answer: It will take 36 hours for the third pipe to fill the pool.----------------------------------------------------------------------------------------
Answer:

Explanation:

Factor out 3

Cancel out the common factor 3

7.6 x 10^2 that's the answer