Answer:
The speed on motorboat is 20 mph
Step-by-step explanation:
here, we want to find the speed on the motorboat
if he has a speed of x mph on the motor boat, his speed on the ski will be (x + 10) mph
The total hours is 4 hours
Mathematically; speed = distance/time
Time on ski is 27/x+ 10
Time on motor boat is 62/x
The addition of both is 4
Thus;
27/(x + 10) + 62/x = 4
27(x) + 62(x + 10) = 4(x)(x + 10)
27x + 62x + 620 = 4(x^2 + 10x)
89x + 620 = 4x^2 + 40x
4x^2 -49x-620 = 0
using the quadratic formula;
{-b ± √(b^2-4ac)}/2a
where a = 4, b = -49 and c = -620
= 49 ± √(-49)^2-4(4)(-620)/8
So we have
49+ 111/8 or 49-111/8
Speed cannot be negative
(49 + 111)/8
= 20 mph
Answer:
the required equation is; y = 21 sin(πt/6)
Step-by-step explanation:
Given the data in the question;
Water rises above sea level = 21 ft
Water drops below sea level = 21 ft
so
maximum = 21 ft and also
minimum = 21 ft
Amplitude = ( maximum + minimum ) / 2
Amplitude = ( 21 + 21 ) / 2
Amplitude = ( 21 + 21 ) / 2 = 42/2 = 21 ft
Period = 12 hours
and we know that; period = 2π/b
so
12 = 2π/b
12b = 2π
b = 2π / 12
b = π/6
Standard equation for simple harmonic is; y = asin(bt)
we substitute
y = 21 sin(πt/6)
Hence the required equation is; y = 21 sin(πt/6)
Answer: No
Step-by-step explanation:
Add 2 sides together. If the sum of greater than the length of the 3rd side for all 3 options it can form a right triangle if it doesn’t than it can’t:
9 + 12 = 21 which is not greater than the 3rd side length of 21 so this cannot form a right triangle.
Answer:
B and C
Step-by-step explanation:
5 * (7 + 6s - 9t) = 7*5 + 6s *5 - 9t*5
= 35 + 30s - 45t
(-35 - 30s + 45t)*(-1) = (-35)*(-1) - 30s *(-1) + 45t*(-1)
= 35 + 30s - 45t
1/ 816
Step-by-step explanation:
Step 1 :
Given
Total number of students in the school = 18
Number of students randomly selected = 3
Step 2 :
Number of ways in which 3 students can be selected out of 18 students is
C(18,3) = 18! /(3!(*18-3)!) = 18*17*16/3*2*1 = 816
Number of ways in which 3 students are selected and they are the youngest = 1
Hence the probability of selecting 3 youngest students from the available students is 1/ C(18,3) = 1/ 816
