CAT
Exam
Numerical Ability
Time and Work
Lakshmi and Divya can complete a data entry jobin X days. Lakshmi alone takes 9 days more to finish the work while Divya take 4 days more. Find the value of X.
(a) 5 days
(b) 13 days
(c) 6 days
(d) 9 days
Read Solution (Total 2)
-
- (c) 6 days
Working alone Lakshmi takes X+9 days and Divya takes X+4 days.
So working together their 1 day work= 1/(X+9) + 1/(X+4) = 1/X
=> (X+4+X+9)/[(X+9)(X+4)] = 1/X
=> 2X^2+13X = X^2 +4X+9X+36
=> X^2= 36
=> X=6 - 8 years agoHelpfull: Yes(0) No(1)
- Working alone Lakshmi takes X+9 days and Divya takes X+4 days.
So working together their 1 day work= 1/(X+9) + 1/(X+4) = 1/X
=> (X+4+X+9)/[(X+9)(X+4)] = 1/X
=> 2X^2+13X = X^2 +4X+9X+36
=> X^2= 36
=> X=+/-6
but time can't be negative
hence 6 is corret - 8 years agoHelpfull: Yes(0) No(0)
CAT Other Question
J,F,M,A,M,?
what is the next letter at shown by question mark??
There are 2 water tanks A and B. A is much smaller than B. While water fills at the rate of 1 litre every hour in A, it gets filled up like 10,20,40,80,160... in B. If tank B is 1/32 filled in 21 hours, then what is the total duration of hours required to fill it completely.
(a) 26
(b) 25
(c) 5
(d) 27