Given:
10 boys clear a piece of land in 21 days.
To find:
The number of days it will take 7 boys to clear the same land at the same rate.
Solution:
We have,
10 boys clear a piece of land in 21 days.
Total work = [tex]10\times 21[/tex]
= [tex]210[/tex]
Let 7 boys clear the same piece of land in x days.
Total work = [tex]7\times x[/tex]
= [tex]7x[/tex]
Now, the total work is same.
[tex]7x=210[/tex]
Divide both sides by 7.
[tex]x=\dfrac{210}{7}[/tex]
[tex]x=30[/tex]
Therefore, 7 boys clear the same piece of land in 30 days.
