Some Questions seeking help! (1 Viewer)

[Effekt]

These questions will be easy for most people but i never did general maths in yr 11 and i think that is where they come from if not let's just assume i am plain stupid working out would be appreciated also!

Huong used the 'capture-recapture' technique to estimate the number of trout living in a dam.
- She caught tagged and released 20 trout
- Later she caught 36 trout at random from the same dam
- She found that 8 of these 36 trout had already been tagged
What estimate should Huong give for the number of trout living in this dam, based on the 'capture-recapture' technique?

Answer: 90 - need working out pls!

And another one

Billy worked 35 hours at normal hourly rate of pay, and for five hours at double time. He earned $561.60 in total for this work.
What was the normal hourly rate of pay?

Answer: $12.48 - need working out pl0x!

 

[Chrissiee]

For Billy:
561.60 (divided by) 45 = $12.48

= 12.48 = normal rate of pay

You divide it by 45 because its double time so the rate 5 hours would turn into the same amount of pay normal time in 10 hours?
did i explain that properly?

 

[Chrissiee]

And for Huong

20 x 36/8 = 90

Total = original number tagged x total recaptured ÷ number tagged on recapture

 

[Effekt]

Thanks heaps!!