Question

I NEED HELP! I don’t get it at all

Answer 1

5.83 cubic feet

Explanation:

Volume of block1 :

l = 4 ft

`\sf w = (5)/(6) \ ft\\\\ h = 1(1)/(6)=(7)/(6) \ ft`

`\sf Volume \ of \ block1 = l*w*h\\`

`\sf =4 *(5)/(6)*(7)/(6)\\\\ =(5)/(3)*(7)/(3)\\\\= (35)/(9) \ cubicfeet`

Volume of block2:

l = 4 ft

`w = 1(2)/(3)-(5)/(6)\\\\ =(5)/(3)-(5)/(6)\\\\ =(5*2)/(3*2)-(5)/(6)\\\\=(10)/(6)-(5)/(6)\\\\w =(5)/(6) \ ft\\\\h =(7)/(12) \ ft`

`\sf Volume \ of \ block2 = 4 *(5)/(6)*(7)/(12)`

`\sf = (5)/(6)*(7)/(3)\\\\= (35)/(18) \ cubicft`

Amount of concrete to build stairs = Volume of block1 + volume of block2

`\sf = (35)/(9)+(35)/(18)\\\\=(35*2)/(9*2)+(35)/(18)\\\\=(70)/(18)+(35)/(18)\\\\=(105)/(18)\\\\= 5.83 \ cubic feet`