Tiger, please advise what is wrong in my calculations:
Total work is 100,000 litres:
a-rate of A hose
b-rate of B hose
100,000/a- time for A hose alone to fill the pool
100,000/b- time for B hose alone to fill the pool
We are asked to find 100,000/(a+b), which reduces to the question what is a+b.
in 1) we are given that after filling a part (1/3 of pool) B worked alone and for a given period of time filled the pool in 22 hours. , so we can calculate b.
we are not provided how much time did it take A and B hose to fill 1/3 of pool, or 33,333 litres., so the 33,333/(a+b)=x hours. hence not sufficeint.
in 2) we are told that it will take hose A 17 hours to fill 50,000 litres of pool, we can calculate a.
50,000/(a+b)=y hours, not sufficient. not suff.
1)& 2) both rates are provided, thus sufficeint to calculate total amount of time. (a+b) , hence C.
Audaces fortuna juvat!
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