Multiply the cost by 1.2 (120%) to add 20% tip, and then multiply by 0.85 (85%) to take off 15%
78.96 x 1.2 x 0.85 = 80.54
Answer:
Step-by-step explanation:
1) ABCD is a trapezium. AB ║ CD
∠ADC + ∠DAB = 180° { Co interior angles}
110° + ∠DAB = 180
∠DAB = 180 -110
∠DAB = 70°
2) Sum of all angles of trapezium = 360°
∠A + ∠B + ∠DCB + ∠D = 360
70° + 50° + ∠DCB + 110° = 360
230 + ∠DCB = 360
∠DCB = 360 - 230
∠DCB = 130°
3) For finding the height, use Pythagorean theorem
height² + base² = hypotenuse²
height² + 6² = 10²
height² + 36 =100
height² = 100 - 36
height² = 64
height = √64
height = 8 m
4) a = AB = x m
b = 9 m
h = height = 8 m
Area of trapezium = 120 m²
= 120

x + 9 = 120/4
x + 9 = 30
x = 30 - 9
x = 21 m
AB = 21m
Answer:
Step-by-step explanation:
Ratio of cakes baked by Calvin and Susie = 3 : 7
Cakes baked by Calvin = 3x
Cakes baked by Susie = 7x
Cakes baked by Calvin = Cakes baked by Susie - 60
3x = 7x - 60
7x - 60 = 3x
7x = 3x + 60
7x - 3x = 60
4x = 60
x = 60/4
x = 15
Cakes baked by Calvin = 3*15 = 45
Cakes baked by Susie = 7 *15 = 105
Total cakes baked = 45 + 105 = 150
They both baked 150 cakes altogether.
Answer:
Surface area of cone is 
Step-by-step explanation:
Given:
radius of a cone (r) = 8 feet
slant height of cone (l) = 12 feet
We need to find the surface area of cone.
Total surface area of cone = Area of circle
Area of curved surface
Now we know that,
Area of circle = 
Area of curved surface = 
Hence Total surface area of cone = 
Surface area of cone is
.
Answer:
see explanation
Step-by-step explanation:
Given that y varies inversely as x then the equation relating them is
y =
← k is the constant of variation
To find k use the condition that x = 9 when y = 15
15 =
( multiply both sides by 9 )
k = 135
y =
← equation of variation