IBPS Clerk Prelims Model Paper 23

Let the total volume of vessel = ‘x’ litres
Initially, the % of spirit in the mixture = 18%
After the replacement of 8 litres of mixture with water, its % = 15%
0.18x – 8 ×

18

100

= 0.15 x
0.03x = 1.44
x = 48 litres
Alternative:
Apply the rule of alligation,

W

S

=

18−15

15−0

=

3

15

=

1

5

Water is 8 litres, so spirit is 40 litres and total mixture is 48 litres.