It will take 60/7 for them to paint the wall.
The unitary method is a method for solving a problem by the first value of a single unit and then finding the value by multiplying the single value.
Working together, we have to find about how long will it take for them to paint the wall.
One student can paint a wall in 15 minutes. Another student can paint the same wall in 20 minutes.
From the given rule ;
(1/x) + (1/y) = (1/z)
1/15 + 1/20 = 1/z
7/60 = 1/z
z = 60/7
Therefore, it will take 60/7 for them to paint the wall.
Learn more about the unitary method;
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