instruction:
In this task, you need to provide the correct option for a given problem from the provided options.
question:
Problem: a jar contains a mixture of two liquids acid ( nitric acid ) and base ( ammonium chloride ) in the ratio 4 : 1 . when 10 litres of the mixture is taken out and 10 litres of liquid base is poured into the jar , the ratio becomes 2 : 3 . how many litres of liquid acid was contained in the jar ?
Options: a ) 14 lts , b ) 18 lts , c ) 20 lts , d ) 16 lts , e ) 26 lts
answer:
d

question:
Problem: how many days per calendar year is the month a factor of the day
Options: a ) 0 , b ) 1 , c ) 59 , d ) 90 , e ) 124
answer:
e

question:
Problem: a bag contains 6 green balls and 7 white balls . if two balls are drawn simultaneously , what is the probability that both balls are the same colour ?
Options: a ) 2 / 7 , b ) 3 / 10 , c ) 5 / 11 , d ) 6 / 13 , e ) 11 / 21
answer:
d