Question

8. एक कार्य को पूरा करने में A को B की तुलना
में 10 दिन कम लगते हैं। यदि तथा B दोनों
मिलकर वह कार्य 12 दिनों में पूरा कर सकते
हों, तो अकेले B को वह कार्य पूरा करने में
कितना समय लगेगा?​

Answer 1

Answer:

The time taken by B alone to complete the work is 30 days.

Step-by-step explanation:

Given as :

The time taken A and B working together = 12 days

The time taken by A is 10 days less than b

Let The time taken by B = x days

Let The time taken by A = x - 10 days

According to question

$\dfrac{1}{A}$ + $\dfrac{1}{B}$ =  $\dfrac{1}{12}$              ......1

So, $\dfrac{1}{x-10}$ + $\dfrac{1}{x}$ =   $\dfrac{1}{12}$    

Or, $\dfrac{x + x - 10}{x (x - 10)}$ =   $\dfrac{1}{12}$    

Or, 12 (2 x - 10) = x ( x - 10 )

Or, 24 x - 120 = x² - 10 x

Or, x² - 10 x - 24 x + 120 = 0

Or,  x² - 34 x + 120 = 0

or, x² - 4 x - 30 x + 120 = 0

Or, x (x - 4) - 30 (x - 4) = 0

Or, (x - 4) (x - 30) = 0

Or, x = 4 , 30

So, The time taken by B = x = 30 days

And Time taken by A = x - 10 = 30 - 10 = 20 days

Hence, The time taken by B alone to complete the work is 30 days. Answer

Answer 2

Answer:

30 days only

Step-by-step explanation:

it takes more time because it is not a Teamwork