Question

If 8 workers can build a wall in 10 days, match the number of workers with the number of days.

• A. 20 days
• B. 40 days
• C. 16 days
• D. 8 days

Answer 1

Since time and number of workers follow inverse proportion for same work, we have
$\text{Time}\times \text{Number of workers}=Constant$

$\text{Let the number of days be}x$
$\text{in each case}$

Case (1) :

$8\times 10=$ $x\times 4$
$\Rightarrow x=20$

Case (2) :

$8\times 10=$ $x\times 2$
$\Rightarrow x=40$

Case (3) :

$8\times 10=$ $x\times 5$
$\Rightarrow x=16$

Case (4) :

$8\times 10=$ $x\times 10$
$\Rightarrow x=8$