How many ounces of a 19% alcohol solution and a 37% alcohol solution must be combined to obtain 90 ounces of a 24% solution

19% alcohol solution = 65 ounces

37% alcohol solution = 25 ounces

Step-by-step explanation:

Let

19% alcohol solution = x

37% alcohol solution = y

x + y = 90 (1)

0.19x + 0.37y = 90*0.24

0.19x + 0.37y = 21.60 (2)

from (1)

x = 90 - y

Substitute into (2)

0.19x + 0.37y = 21.60

0.19(90-y) + 0.37y = 21.60

17.1 - 0.19y + 0.37y = 21.60

- 0.19y + 0.37y = 21.60 - 17.1

0.18y = 4.5

y = 4.5/0.18

y = 25 ounces

x + y = 90 (1)

x + 25 = 90

x = 90 - 25

x = 65 ounces

The answer is in the image 

The answer is in the image 

The answer is in the image 

The solution is given in the image below

Here,

tip=18%of $32

tip=(18/100)*32

=0.18*32

=$5.76

Total payment=32+5.76=$37.76

Speed=Distance/time

Here,

distance=15m

time=1sec

speed=15/1=15m/sec

Distance=Speed*time

time=15min=15*60sec=900sec

Distance travelled in 15 min=15*900=13,500m

=13500/1000 km=13.5Km

The wood before starting =12 feet

Left wood=6 feet

Wood used till now=12-6=6 feet

Picture frame built till now= 6/(3/4)

=8 pieces

Therefore, till now 8 pieces have been made.

The wood before starting =12 feet

Left wood=6 feet

Wood used till now=12-6=6 feet

Picture frame built till now= 6/(3/4)

=8 pieces

Therefore, till now 8 pieces have been made.