Respuesta :
Answer:
Therefore the wall contained 900 bricks.
Step-by-step explanation:
Given that there are two bricklayers.
In 9 hours, the first bricklayers built a certain wall and other bricklayer takes 10 hours to build the wall.
Let b = the number of bricks of the wall.
The number brick laid in 9 hour by first bricklayer is b
Then the number brick laid in 1 hour by first bricklayer is [tex]\frac{b}{9}[/tex].
The number brick laid in 5 hour by first bricklayer is [tex]\frac{5b}{9}[/tex].
The number brick laid in 10 hour by second bricklayer is b
Then the number brick laid in 1 hour by second bricklayer is [tex]\frac{b}{10}[/tex]
Then the number brick laid in 5 hour by second bricklayer is [tex]\frac{5b}{10}[/tex]
Again given that, if they worked together 10 fewer bricks got laid per hour.
If they worked together for 5 hours,then (5×10)=50 less bricks were laid by them.
The number of brick were laid by them is [tex]=\frac{5b}{9}+\frac{5b}{10}-50[/tex].
But the wall made by b number of bricks.
According to the problem,
[tex]\frac{5b}{9}+\frac{5b}{10}-50=b[/tex]
[tex]\Rightarrow \frac{50b+45b-4500}{90}=b[/tex] [ The L.C.M of 9 and 10 is =10]
[tex]\Rightarrow{50b+45b-4500=90b[/tex]
[tex]\Rightarrow 95b-4500=90b[/tex]
[tex]\Rightarrow 95b-90b=4500[/tex]
[tex]\Rightarrow 5b=4500[/tex]
[tex]\Rightarrow b=\frac{4500}{5}[/tex]
[tex]\Rightarrow b=900[/tex]
Therefore the wall contained 900 bricks.
