Answer:
20 gallons were used from the tank with the octane rating of 80.
Step-by-step explanation:
Given : One tank of gasoline has an octane rating of 140 and another tank of gasoline has an octane rating of 80. To obtain a mixture of 60 gallons with an octane rating of 120.
To find : How many gallons should be used from the tank with the octane rating of 80?
Solution : Let x be the volume of gas whose octane rating is 140 and
y be the volume of gas whose octane rating is 80.
Then, we form the equation as:
(1) 

or
.........[3]
(2) 
Now multiply equation (2) by 4
...........[4]
Subtract (4) from (3)



Put x in equation [4] we get,





Therefore, x=40 and y=20
So, 20 gallons were used from the tank with the octane rating of 80.





Now,







Area of rectangle = 38.5 cm².
It’s represents the coupon for each shirt being taken on the price of each shirt
Answer:
1058.4 in^2
Step-by-step explanation:
Find the surface areas of the rectangular prism and the triangular prisms separately.
Triangular: S = (1/2)lP+B, where l is slant height, P perimeter, and B base area.
14(4)= 56 perimeter of base
13 slant height
B = 14x14 = 196
put together:
S = (1/2)(13 x 56) + 196
S = 560 in^2
Now the rectangular prism
S = 2lw + 2lh + 2wh, where l is length, h height, w width. (delete the first 2lw since they share one side/they're combined shapes.
S = 2(14x8.9) + 2(14x8.9)
S = 498.4 in^2
Add them together: 498.4 + 560 = 1058.4 in^2
1/10, 3/10, 0.9
Hope this Helps