Answer:
1 3/7 quarts should be drained off and replaced with pure antifreeze.
1 3/7 ≈ 1.4286
Current amount of antifreeze in quarts is -
30/ 100 × 10 = 3
40% ---> 4 quarts
Let the amount drained of and replaced with antifreeze be x-
The amount left after draining off is 10 − x.
The amount of antifreeze is 30/ 100 (10−x).
30/100(10-x)+x=4
3-3/10x+x=4
3+x(1-3/10)=4
x=1*10/7=1 3/7 quarts
check;
10- 1 3/7 = 8 4/7
=(30/100*8 4/7)+1 3/7
=(3/10 * 60/7) + 10/7
=3*6/7 + 10/7
=28/7
=4
4 liters of pure antifreeze is mixed into 10 quarts.
Answer:
last one.................
