First account: $6500
Second account: $8500
Set x is amount of money in first account
=> x + 2000 is money in second account.
X*3% + (x+2000)*4% = 535
=> x = (53500 - 8000) / 7
X = 45500 / 7 = 6500
=> account #1 = x = 6500
Acc #2 = x + 2000 = 6500 + 2000 = 8500
from the given equation
X+Y=20-->i
X-Y=14--->ii
add eq i and eq ii
2x=34
x=17
putting the value of x=17 in eq i
17+y=20
then y = 3 so the right answer is
17 and 3
You can calculate them out and check which one is the most accurate
so if one of the choices was 1/3 of 50, then you would do:
1/3 in the calculator (should be 0.333...) times 50
And you can compare it with the EXACT number, which is:
0.25*53=13.25
This way you can test all the options
To Find :
How many gallons of a 80% antifreeze solution must be mixed with 100 gallons of 20% antifreeze to get a mixture that is 70% antifreeze.
Solution :
Let, x gallons of 80% antifreeze solution is required :
So,

Therefore, 500 gallons of 80% antifreeze solution is required.