Question

Roshan alone can build a fence in 20 days he starts the work and leaves it after 5 days Ramesh does the remaining work in 12 days how long will it take if Ramesh did the whole work alone how long will it take if Roshan and Ramesh work together from the beginning

Answer 1

One day work of roshan
$\frac{1}{20}$
therefore work done by him
$\frac{1}{20} \times 5 = \frac{1}{4}$
remaining work
$1 - \frac{1}{4} = \frac{3}{4}$
let ramesh one day work be
$\frac{1}{x}$
therefore
$\frac{1}{x} \times 12 = \frac{3}{4}$
$\frac{1}{x} = \frac{3}{48} = \frac{1}{16}$
ramesh one day work is 1/16
ramesh can complete the work in 16 days
now if they work togather then their one day work=1/20+1/16=4+5/80=9/80
implies 80/9 days
=8whole8/9 days

Answer 2

Answer:

One day work of roshan

\frac{1}{20}

20

1

therefore work done by him

\frac{1}{20} \times 5 = \frac{1}{4}

20

1

×5=

4

1

remaining work

1 - \frac{1}{4} = \frac{3}{4}1−

4

1

=

4

3

let ramesh one day work be

\frac{1}{x}

x

1

therefore

\frac{1}{x} \times 12 = \frac{3}{4}

x

1

×12=

4

3

\frac{1}{x} = \frac{3}{48} = \frac{1}{16}

x

1

=

48

3

=

16

1

ramesh one day work is 1/16

ramesh can complete the work in 16 days

now if they work togather then their one day work=1/20+1/16=4+5/80=9/80

implies 80/9 days

=8whole8/9 days