Please solve this question

Asked by Krishna Omar on 2026-08-23 in CAT Prep

Two tanks, T1​ and T2​, each having the same capacity, are fitted with inlet taps A and B, which fill at different rates. Initially, tap A starts filling T1​. After 7 minutes, tap B is turned on to fill T2​. Nine minutes later, the combined volume of water in both tanks equals the capacity of a single tank. After exactly T more minutes, both tanks are completely filled. What is the value of T?

1 Answer

Saidarshan Nayak · 2026-08-23 · 2 helpful

given rate of a and b
in first tank 7xa then for 9minutes 9a=total(16a)
in second tank is
9b so
it say 16a+9b= capacity of one tank[the combined volume of water in both tanks equals the capacity of a single tank.]
so both the tank have capacity of 16a+9a each

in first tank 16a is done so remaining is 9b
and in 2nd tank 9b is done so remain is 16a

then question says t minutes requires to fill the both tank
so
t=9b/a=16a/b(time= remaining work/rate of work done)
cross multiply
9b^2=16a^2
>b^2/a^2=16/9
b/a=4/3
so b=4 a=3

so t=9b/a or 16a/b
9x4/3=12 or 16x3/4=12
ans is 12 minutes

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