RRB Paramedical Staff Nurse Model Paper 3

Given, Time taken by (A+B) to fill the tank =6h
Thus, part of tank filled by A + B in 1h=‌

1

6

..... (i)
(if a pipe fills a tank in x h, then the part of tank filled in 1h=‌

1

x

)
Similarly, part of tank filled by (B + C) in 1h. =‌

1

10

.....(ii)
And part of tank filled by (C + A) in 1h=‌

2

15

......(iii)
Now, part of tank filled by (A + B + C) in 1h
On adding Esq. (i), (ii), (in), we get
A+B+B+C+C+A
=‌

1

6

+‌

1

10

+‌

2

15

⇒2A+2B+2C=‌

5+3+4

30

⇒2(A+B+C)=‌

12

30

⇒‌‌(A+B+C)=‌

12

60

⇒‌‌(A+B+C)=‌

1

5

Hence, A, B and C all three can fill the tank in 5h
(if a pipe fills ‌

1

x

part of the tank in 1h, then the time taken by the pipe to fill the full tank =xh )