Question

It takes 63 minutes for 4 people to paint 9 walls.

Answer 1

63 / 9 = 7
7 / 4 = 1.75
It takes 1.75 minutes for 1 person to paint 1 wall...
1.75 * 4 = 7
7 * 7 = 49
It took 49 minutes for 7 people to paint 4 walls...

Answer 2

Answer:

7 people will take 16 minutes to paint 4 walls.

Step-by-step explanation:

Since, if $x_1$ people take $n_1$ times for $w_1$ work and in the same kind of work $x_2$ people take $n_2$ time for $w_2$ work,

Then,

$\frac{x_1\times n_1}{w_1}=\frac{x_2\times n_2}{w_2}$

Here, $x_1=4$, $n_1=63$, $w_1=9$,

$x_2=7$, $w_2=4$

By substituting the values in the above formula,

$\frac{4\times 63}{9}=\frac{7n_2}{4}$

By the cross multiplication,

$1008=63n_2$

$\implies n_2=\frac{1008}{63}=16$

Hence, 7 people will take 16 minutes to paint 4 walls.