# write a proportion that could be used to solved for the variable.then solve 16 walls in 40 hours, 3 walls in h hours

hala718 | High School Teacher | (Level 1) Educator Emeritus

Posted on

16 walls in 40 ours

3  walls in  h hours

We are going to use ratio properties :

3*40= 16 *h

==> h= 3*40 /16 = 120/16= 12/2 = 7.5 hours.

pohnpei397 | College Teacher | (Level 3) Distinguished Educator

Posted on

The way to set this up is to express it in terms of walls per hour.  So in walls per hour, the first of these is

16/40

Both of these are divisible by 8 so we can say that 16 walls in 40 hours is equal to

2 walls per 5 hours or 2/5

Now, this means that

2/5 = 3/h

By solving for h, we will know how many hours it takes to do 3 walls.  We can solve for h by cross multiplying.  That gives us

2h = 5*3

2h = 15

h = 7.5

So at the rate of 16 walls in 40 hours, 3 walls will take 7.5 hours.

neela | High School Teacher | (Level 3) Valedictorian

Posted on

16 walls in 48 hours ,3walls in h  hours.

Solution:

The required proportion is 16 walls : 40 hours = 3 walls: h hours. Or

40 hrs : 16walls = h hrs : 3walls

Or

16 walls/40 hours = 3walls /h hours . This implies the numbers of walls constructed per hour is same. Or

Therefore  h/3 = 40/16 in pure ratio.

So h = (40/16)3 = 7.5 hrs.