Question

A and b together can complete a work in 8 days and b and c together in 12 days. all of them together can complete the work in 6 days. in how much time will a and c together completer the work? 1) 8 days 2) 10 days 3) 12 days 4) 20 days

Answer 1

A AND B 1 DAY WORK 1/8 FIRST EQUATION

B AND C 1 DAY WORK 1/12 SECOND EQUATION

A,B AND C 1 DAY WORK 1/6 THIRD EQUATION

THIRD MINUS FIRST 1/6 - 1/8 GIVES C=2/48=1/24

THIRD MINUS SECOND GIVES A =1/6 -1/12=6/72=1/12

NOW A+B=1/8 IMPLIES 1/12+B=1/8

B=1/8 -1/12= 4/96=1/24

A ,B AND C FINISHES IN 12, 24 AND 24 DAYS.