Answer:
c
Step-by-step explanation:
In order to answer this one, it's really really really really helpful if you know what the law of cosines says. In fact it's absolutely necessary.
The law of cosines says if you know two sides of a triangle and the angle between them then you can use that information to find the length of the third side.
In the picture you know the lengths of two sides and you know the angle between them. So you can use the law of cosines to find the length of the third sidethat. That's side AC.
2 litres every 2.5 minutes is 4 litres every 5 minutes so therefore, it is 0.8 litres/minute (800ml per minutes)
Read the question carefully: it costs 4 tokens to park in a garage for an hour.
We will apply the unitary method to solve this question
It costs 4 tokens to park in a garage for 1 hour
Find how many hours can park in a garage for 1 token
If it costs 4 token to park in a garage for 1 hour
Then it will cost 1 token to park in a garage for 1/4 hour
Step2:
With 20 token we can park in a garage for (1/4) * 20
= 5 hours
So, we can park for 5 hours with 20 tokens.
Another method
If we take twenty tokens and divide them into groups of four, we will find that we are left with five groups of tokens. Each group of tokens represents an hour of parking time. This will give us five groups, or five hours, total.
So, we can park for 5 hours with 20 tokens
