Question

12 painters can paint a wall of 180 m long in 3 days. How many painters are required to paint a 200 m long wall in 5 days?

• A. $18$
• B. $24$
• C. $20$
• D. $8$

Answer 1

The correct option is D $8$

$Since,numberofpainters\alpha lengthofthewalland,$

$numberofpainters\alpha \frac{1}{numberofdays}$

Therefore, 12 : x $=$ compound ratio of 9 : 10 and 5 : 3

So, 12 : x = (9 : 10) × (5 : 3)
Or, 12 : x = 9 × 5 : 10 × 3
Or, 12 : x = 45 : 30
Or, 12 : x = 3 : 2
$\therefore x=\frac{12\times 2}{3}=8$
Thus, $8$ painters are required to paint a $200m$ long wall in $5$ days.