Question

8. A can finish a piece of work in 15 days and B can do it in 10 days. They worked together for 2 days and then B goes away. In how many days will A finish the remaining work?​

Answer 1

Given :

• A = 15 days
• B = 10 days
• A + B = 2 days

To find :

• No. of. Days A would need to complete the remaining work

Solution :

Let,

• A's 1 day work be = $\sf{\dfrac{1}{15}}$
• B's 1 day work be = $\sf{\dfrac{1}{10}}$
• A + B's 1 day work be = $\sf{\dfrac{1}{2}}$

To find the No. of. Days A would need to complete the remaining work,

$\boxed{A\:+\:B's\:1\:day\:work\:-\:B's\:1\:day\:work\:=\:A's\:work}$

Substituting the values :

$\implies\sf{\dfrac{1}{2}}\:-\:{\dfrac{1}{10}}$

$\implies\sf{\dfrac{5\:-\:1}{10}}$

$\implies\sf{\dfrac{4}{10}}$

$\implies\sf{2.5}$

Hence, A would need 2 days and 5 hours to complete the remaining work.