CBSE Class 10 Answered

a tank of dimensions 70cm x 40cm x 25cm is half filled. if tap A takes 5 minutes to fill the remaining part whereas tap B removes the water in the tank at the rate of 10.5 litres per minute. find the time taken to fill 3/10 volume of water in the tank when both taps are kept on?

Asked by Āß | 19 Mar, 2017, 05:51: AM

Expert Answer

Dear student, yesterday you wrote 'a tank of dimensions 70cm x 40cm x 25cm if half filled'.

Today you wrote 'a tank of dimensions 70cm x 40cm x 25cm is half filled'.

This changes the meaning of the question.

if means we are considering the dimesions of the tank to be equal to the amount of water filled.

is means we are considering the dimensions of the whole tank.

begin mathsize 12px style straight A space tank space of space dimensions space 70 space cm space straight x space 40 space cm space straight x space 25 space cm space i s space half space filled. space rightwards double arrow Volume space of space half space of space the space tank space equals fraction numerator 70000 space over denominator 2 end fraction equals 35 space litres space left parenthesis Since space 1 space litres equals 1000 space cm cubed right parenthesis Volume space of space half space of space the space tank space equals 35 space litres Tap space straight A space takes space 5 space minutes space to space fill space the space remaining space part comma space that space is comma space half space of space the space tank. So comma space the space rate space at space which space tap space straight A space fills space half space of space the space tank space equals space 35 over 5 equals 7 space litres divided by min Given space that space Tap space straight B space removes space the space water space in space the space tank space at space the space rate space of space 10.5 space litres divided by minute. 3 over 10 left parenthesis Volume space of space the space tank right parenthesis equals 3 over 10 left parenthesis 70 right parenthesis equals 21 space litres H e r e space t h e space r a t e space o f space t a p space A space i s space l e s s space t h a n space t h a t space o f space t a p space B comma space s o space i t space i s space n o t space p o s s i b l e space t o space f i l l space t h e space tan k space i n space t h i s space s c e n a r i o. end style

I have sent you yesterday the same question using if. Please check. Thank you.

Please check that solution, since the rate of tap A has to be more than that of B for the tank to fill.

Here is the link:

http://www.topperlearning.com/forums/ask-experts-19/a-tank-of-dimensions-70cm-x-40cm-x-25cm-if-half-filled-tap-mathematics-arithmetic-progression-nth-term-of-an-ap-101171/reply

Do let me know if you did not understand any step or you have a doubt. Thank you.

Answered by Rebecca Fernandes | 19 Mar, 2017, 12:38: PM