Answer:
C
Step-by-step explanation:
The circumference (C) of a circle = 2πr ← r is the radius
Given C = 15π the equating gives
2πr = 15π ( divide both sides by 2π )
r =
= 7.5 cm
The area (A) of a circle is calculated using the formula
A = πr² = π × 7.5² = 56.25π cm² → C
43.0810
Since the hundred thousandths is a 1 which is less than a 5, you have to round down.
Answer:
A
Step-by-step explanation:
Given
= 30 ( square both sides to clear the radical )
qrv + 11 = 900 ( subtract 11 from both sides )
qrv = 889 ( divide both sides by rv )
q =
→ A
Answer:
Step-by-step explanation:
<u>This is going to be an arithmetic progression:</u>
- 48500, 48500 + 1200, 48500 + 1200*2, ...
<u>So the first term is </u>
<u>and the common difference is </u>
<u>Sum of AP is:</u>
- S = (a₁ + aₙ)*n/2 = (2a₁ + (n - 1)d)*n/2
<u>Substitute and solve for n:</u>
- (2*48500 + (n - 1)*1200)*n/2 = 321000
- (97000 + 1200n - 1200)n = 642000
- 1200n² + 95800n - 642000 = 0
- 6n² + 479n - 3210 = 0
<u>Solving we get a positive root of:</u>
- n ≈ 6.21 and it rounds up to 7 years
It is 15x because you multiply 3 and 5 and keep your x with it