Question

a can do apiece of work in 30days while B alone can do it in 40 days in how many days can And B working together

Answer 1

Hey there


Let us name A as Raj and B as rohan

according to the question

since , Raj's one day's work = 1/30 part

and Rohan's one day's work = 1/40 part

Therefore , Raj and Rohan's one day work

$\frac{1}{30} + \frac{1}{40} \\ \\ = > \frac{4 + 3}{120 } \\ \\ = > \frac{7}{120}$

Number of days taken by raj and rohan together to complete the work

=
$1 \div \frac{7}{120} \\ \\ = > \frac{120}{7} \\ \\ \: \: \: \: or \: \: \: \: 17 \ \frac{1}{7} \: \: days \:$
Hope this would help you