Answer: they left home at 8:38
Work:
8:45 + 20 mins = 9:05 (time they arrived)
9:05 - 27 mins = 8:38 (time they left)
Answer:
a) 28,662 cm² max error
0,0111 relative error
b) 102,692 cm³ max error
0,004 relative error
Step-by-step explanation:
Length of cicumference is: 90 cm
L = 2*π*r
Applying differentiation on both sides f the equation
dL = 2*π* dr ⇒ dr = 0,5 / 2*π
dr = 1/4π
The equation for the volume of the sphere is
V(s) = 4/3*π*r³ and for the surface area is
S(s) = 4*π*r²
Differentiating
a) dS(s) = 4*2*π*r* dr ⇒ where 2*π*r = L = 90
Then
dS(s) = 4*90 (1/4*π)
dS(s) = 28.662 cm² ( Maximum error since dr = (1/4π) is maximum error
For relative error
DS´(s) = (90/π) / 4*π*r²
DS´(s) = 90 / 4*π*(L/2*π)² ⇒ DS(s) = 2 /180
DS´(s) = 0,0111 cm²
b) V(s) = 4/3*π*r³
Differentiating we get:
DV(s) = 4*π*r² dr
Maximum error
DV(s) = 4*π*r² ( 1/ 4*π*) ⇒ DV(s) = (90)² / 8*π²
DV(s) = 102,692 cm³ max error
Relative error
DV´(v) = (90)² / 8*π²/ 4/3*π*r³
DV´(v) = 1/240
DV´(v) = 0,004
Boys:girls = 4/5
boys = 4/(4+5) = 4/9 of the class
Answer:
7/10 < 3/4
Step-by-step explanation:
7/10 = 14/20
3/4 = 15/20
7/10 < 3/4
Answer:
78
Step-by-step explanation:
for the right side we can just do 14*2 since there are two people per seat and 14 rows
14 *2 is 28
for the left side we just do 14*3 since there are three people per seat and 14 rows
14*3 is 42
Then we have to add the 8 students that can fit in the very back seat
42 + 28 + 8
28 + 8 is 36
42 + 36 = 78
