Answer:
Add 1.25 litres of oil.
Step-by-step explanation:
Contents in beaker A implies;
15% of oil in 1 litre = 0.15 litres of oil
So that, there are 0.15 litres of oil and 0.85 litres of vinegar in beaker A.
Contents in beaker B implies:
55% of oil in 2 litres = 1.1 litres of oil
So that, thee are 1.1 litres of oil and 0.9 litres of vinegar in beaker B.
Half of contents of B poured into A implies that beaker A now contains:
0.15 litres + 0.55 litres = 0.7 litres of oil
0.85 litres + 0.45 litres = 1.3 litres of vinegar
The percentage of oil in A now = x 100%
= 35%
To increase the percentage of oil to 60%, then:
0.7 litres + 1.25 litres = 1.95 litres of oil
But the new total litres of the content in beaker A = 3.25 litres
So that;
x 100% = 60%
Therefore, to produce a mixture which is 60% oil, add 1.25 litres of oil.