Since the beacons rotate together, the angular speed is constant.
From the time you see the first beacon, you have to wait for the lighthouse to make 120°, i.e. 1/3 of a whole turn.
So, if T is the time it takes for the lighthouse to make a whole turn, the interval between the first and the second beacon is T/3.
The interval between the second and third beacon is the amount of time it takes to the lighthouse to make the remaining 2/3 of a turn, so that you'll see the first beacon again. So, this time is 2T/3
So, the ratio is
So, the time between the second and third beacon is twice as much the time between the first two.
The answer is 17/18.
You need to make the denominator the same on all the fractions.
Hope this helps.
Answer:
2nd option
Step-by-step explanation:
r + 1 = 23 ( subtract 1 from both sides )
r = 22 ( multiply both sides by 3 to clear the fraction )
r = 66 ( divide both sides by )
r = 
× 
( rationalising the denominator )
r = 
= 33
Statement Reason
1. 
Given
2. 
Distributive property of multiplication over addition
Let 'a', 'b' and 'c' be any real numbers. So, Distributive property of multiplication over addition states a(b+c) = ab + ac
3. 
Subtraction property of order
4. 
Addition property of equality
The addition property of equality states that if the same number is added to both sides of an equation, then the equation is still true.
5. x<1 Division property of equality
The Division Property of Equality states that if you divide both sides of an equation by the same nonzero number, the equation remain equal.
2 to the third power is 2³
so 2 to the third power times -5 is 2³ * (-5)
which on simplification will be 8* (-5) =-40
