There are three drains in a 6-meter-deep reservoir of water. to lower the water level by 2 meters it takes drain a 2 hours, drain b 3 hours, and drain c 4 hours. if all three drains are opened at once, how long will it take to empty the reservoir?

answer is c

step-by-step explanation:

81/12=324/x

x=48

an = 22 + (n-1) *6

110 seats

step-by-step explanation:

an=a1+(n-1)(d)

a1 = 22   this is the first item in the sequence

d =6   this is how the sequence goes up

a)   an = 22 + (n-1) *6

b) a12 = 22 + (12-1) *6

    a12 = 22+11*6

  a12 = 22 +88

  a12 = 110

your answer is  

d.

196.5 m2

step-by-step explanation: