Answer:
A
Step-by-step explanation:
Given the 2 equations
x = 3 - y → (1)
5x - 12 = y → (2)
Substitute x = 3 - y into (2)
5(3 - y) - 12 = y ← distribute and simplify left side
15 - 5y - 12 = y
3 - 5y = y ( add 5y to both sides )
3 = 6y ( divide both sides by 6 )
= y, that is
y = 0.5 → A
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.