Answer:
Dylan delivered 140 parcels on Wednesday.
Step-by-step explanation:
On Wednesday:
On Wednesday, he delivered x parcels.
Thursday:
10% more than Wednesday, so 100 + 10 = 110% of x = 1.1x
Friday:
50% pless than on Thursday, so 100 - 50 = 50% of 1.1x = 0.5*1.1*x.
THis is equals to 77. So
Dylan delivered 140 parcels on Wednesday.
Answer:
1) ΔACD is a right triangle at C
=> sin 32° = AC/15
⇔ AC = sin 32°.15 ≈ 7.9 (cm)
2) ΔABC is a right triangle at C, using Pythagoras theorem, we have:
AB² = AC² + BC²
⇔ AB² = 7.9² + 9.7² = 156.5
⇒ AB = 12.5 (cm)
3) ΔABC is a right triangle at C
=> sin ∠BAC = BC/AB
⇔ sin ∠BAC = 9.7/12.5 = 0.776
⇒ ∠BAC ≈ 50.9°
4) ΔACD is a right triangle at C
=> cos 32° = CD/15
⇔ CD = cos32°.15
⇒ CD ≈ 12.72 (cm)
Step-by-step explanation:
Answer:
Mean age: 48
Standard deviation: 4
Step-by-step explanation:
a) Mean
The formula for Mean = Sum of terms/ Number of terms
Number of terms
= 42 + 54 + 50 + 54 + 50 + 42 + 46 + 46 + 48+ 48/ 10
= 480/10
= 48
The mean age is 48
b) Standard deviation
The formula for Standard deviation =
√(x - Mean)²/n
Where n = number of terms
Standard deviation =
√[(42 - 48)² + (54 - 48)² + (50 - 48)² +(54 - 48)² + (50 - 48)² +(42 - 48)² + (46 - 48)² + (46 - 48)² + (48 - 48)² + (48 - 48)² / 10]
= √-6² + 6² + 2² + 6² + 2² + -6² + -2² + -2² + 0² + 0²/10
=√36 + 36 + 4 + 36 + 4 + 36 + 4 + 4 + 0 + 0/ 10
=√160/10
= √16
= 4
The standard deviation of the ages is 4
Answer:Robert's minimum age is 11 years.
Step-by-step explanation:
Let x represent George's age.
Let y represent Edward's age.
Let z represent Robert's age.
George is twice as old as Edward. It means that
x = 2y
Edward's age exceeds Robert's age by 4 years. It means that
z = y - 4
If the sum of the three ages is at least 56 years, it means that
x + y + z ≥ 56 - - - - - - - - - - 1
Substituting x = 2y and z = y - 4 into equation 1, it becomes
2y + y + y - 4 ≥ 56
4y - 4 ≥ 56
4y ≥ 56 + 4
y ≥ 60/4
y ≥ 15
z = y - 4 = 15 - 4
z ≥ 11
Answer:
8m-4=16
8m=20
m=2.5
Step-by-step explanation:
