Bonjour,
answer ≈ 522.92
working
A= 2πrh+2πr^2
=2 x π x 4 x 18+2 x π x 4^2
≈552.92031
Number of pounds of macadamia nuts is 8 pounds and number of pounds of almonds is 4 pounds.
<u>Step-by-step explanation:</u>
Step 1:
Given total pounds of mixture = 12 pounds, cost of macadamia nuts per pound = $9, cost of almonds per pound = $5.25, total cost of mixture per pound = $7.75.
Let number of pounds of macadamia nuts be x and number of pounds of almonds be 12-x.
Step 2:
Form an equation using the above information.
⇒ 9x + 5.25 (12-x) = 12 × 7.75
⇒ 9x + 63 - 5.25x = 93
⇒ 9x - 5.25x = 30
⇒ 3.75x = 30
⇒ x = 8
Number of macadamia nuts is 8 pounds.
Step 3:
Calculate number pounds of almonds
⇒ Number of pounds of almonds = 12 - x = 4 pounds.
Answer:
740
Step-by-step explanation:
The n th term of an arithmetic series is
= a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Given a₃ = 7 and a₇ = (3 × 7) + 2 = 21 + 2 = 23 , then
a₁ + 2d = 7 → (1)
a₁ + 6d = 23 → (2)
Subtract (1) from (2) term by term
4d = 16 ( divide both sides by 4 )
d = 4
Substitute d = 4 into (1)
a₁ + 2(4) = 7
a₁ + 8 = 7 ( subtract 8 from both sides )
a₁ = - 1
The sum to n terms of an arithmetic series is
= 
[ 2a₁ + (n - 1)d ] , thus
= 
[ (2 × - 1) + (19 × 4) ]
= 10(- 2 + 76) = 10 × 74 = 740
I believe it would be the second option....
