উত্তর সিলেক্ট করলে সঠিক ও ভুল দেখাবে।
ব্যাখ্যা ও সঠিক সমাধান
উত্তর:
10Days
(A + B) can do in 1 day = 1/12 th of the work
(B + C) can do in 1 day = 1/15 th of the work
(C + A) can do in 1 day = 1/20 th of the work
So, In 1 day 2 (A + B + C) can do ( 1/12 + 1/15 + 1/20) portion
= ( 5 + 4 + 3)/60 portion
= 12/60 portion
= 1/5 portion
In 1 day( A + B + C) can do = 1/(5×2) portion = 1/10 portion
(A + B + C) can do 1/10 portion in 1 day
" " " 1 " " = 1×10 day = 10 days