A and B together can paint a room in 18days. They work together for8days and then B goes away.  A finishes the rest of work in 15days. How long would each take to finish the working separeately

Asked by acanilchauhan7 | 5th Nov, 2019, 11:50: PM

Expert Answer:

Work done by A and B together is
open parentheses 1 over A plus 1 over B close parentheses 18 equals 1 space.... space left parenthesis i right parenthesis
T h e y space w o r k space 8 space d a y s space t o g e t h e r space a n d space t h e n space B space g o e s space a w a y comma space A space c o m p l e t e space t h e space r e s t space o f space w o r k space i n space 15 space d a y s
rightwards double arrow 1 over A left parenthesis 8 plus 15 right parenthesis plus 1 over B 8 equals 1 space.... space left parenthesis i i right parenthesis
S o l v i n g space left parenthesis i right parenthesis space a n d space left parenthesis i i right parenthesis space s i m u l a tan e o u s l y comma space w e space h a v e
A equals 27 space d a y s space a n d space B equals 54 space d a y s
open parentheses 1 over A plus 1 over B close parentheses 18 equals 1 space.... space left parenthesis i right parenthesis
T h e y space w o r k space 8 space d a y s space t o g e t h e r space a n d space t h e n space B space g o e s space a w a y comma space A space c o m p l e t e space t h e space r e s t space o f space w o r k space i n space 15 space d a y s
rightwards double arrow 1 over A left parenthesis 8 plus 15 right parenthesis plus 1 over B 8 equals 1 space.... space left parenthesis i i right parenthesis
S o l v i n g space left parenthesis i right parenthesis space a n d space left parenthesis i i right parenthesis space s i m u l a tan e o u s l y comma space w e space h a v e
A equals 27 space d a y s space a n d space B equals 54 space d a y s

Answered by Renu Varma | 6th Nov, 2019, 10:51: AM