Question -
Answer -
Two pipes can fill the .reservoir in = 12 hours
Let first pipe can fill the reservoir in = x hrs
Then second pipe will fill it in = (x тАУ 10) hours
Now according to the condition,
┬а
=> x┬▓ тАУ 10x = 24x тАУ 120
=> x┬▓ тАУ 10x тАУ 24x + 120 = 0
=> x┬▓ тАУ 34x + 120 = 0
=> x┬▓ тАУ 30x тАУ 4x + 120 = 0
=> x (x тАУ 30) тАУ 4 (x тАУ 30) = 0
=> (x тАУ 30) (x тАУ 4) = 0
Either x тАУ 30 = 0, then x = 30
or x тАУ 4 = 0 but it is not possible as it is < 10
The second pipe will fill the reservoir in = x тАУ 10 = 30 тАУ 10 = 20 hours