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Could you help me with this question.
A lake contains frogs, tadpoles,fish,and ducks in the ratio 3:7:3:2 respectively. In 750m^(2) of the lake, there are 83 tadpoles. 36 ducks move into the lake from a nearby pond. The whole lake is 4500m^(2)
(It's 5 marks)
Reply 1
Original post by Maths1210
Could you help me with this question.
A lake contains frogs, tadpoles,fish,and ducks in the ratio 3:7:3:2 respectively. In 750m^(2) of the lake, there are 83 tadpoles. 36 ducks move into the lake from a nearby pond. The whole lake is 4500m^(2)
(It's 5 marks)


You don't appear to have finished the question. If you do then I'm happy to take a look.
Reply 2
Original post by AstroST
You don't appear to have finished the question. If you do then I'm happy to take a look.


A lake contains frogs, tadpoles, fish , and ducks in the ratio 3:7:3:2 respectively.
a) in 750m^(2) of the lake there are 84 tadpoles. Work out the total number of frogs and fish in this section of the lake. (2 marks).

b) 36 ducks move into the lake from a nearby pond. The whole lake is 4500m^(2).
Work out the new ratio of
frogs:tadpoles:fish: ducks. Give your answer on form 6:a:b:c. (5 marks)
Thanks so much.
Reply 3
Original post by Maths1210
A lake contains frogs, tadpoles, fish , and ducks in the ratio 3:7:3:2 respectively.
a) in 750m^(2) of the lake there are 84 tadpoles. Work out the total number of frogs and fish in this section of the lake. (2 marks).

b) 36 ducks move into the lake from a nearby pond. The whole lake is 4500m^(2).
Work out the new ratio of
frogs:tadpoles:fish: ducks. Give your answer on form 6:a:b:c. (5 marks)
Thanks so much.


Ok, for part a), we have the ratio 3:7:3:2. We can rescale this ratio provided we multiply every bit by the same amount. So we could say 6:14:6:4 or 9:21:9:6 etc. We know that in this section of the lake, there are 84 tadpoles, so we can rescale the ratio to be 36:84:36:24. From this can you see what the number of frogs and fish in this section is?

In part b), the whole lake gains 36 extra ducks. As the whole lake is 4500m^2, in a 750m^2 section, there will be an extra 6 ducks, as 750m^2 is 1/6th of the total lake, and 1/6th of 36 is 6. Therefore, the ratio we found in a) needs to gain an extra 6 ducks, becomming 36:84:36:30, to get it in the form 6:a:b:c you need to divide all parts by 6 (as 36/6=6 gives the 6 we want for the entry in the ratio).
Reply 4
Original post by AstroST
Ok, for part a), we have the ratio 3:7:3:2. We can rescale this ratio provided we multiply every bit by the same amount. So we could say 6:14:6:4 or 9:21:9:6 etc. We know that in this section of the lake, there are 84 tadpoles, so we can rescale the ratio to be 36:84:36:24. From this can you see what the number of frogs and fish in this section is?1

In part b), the whole lake gains 36 extra ducks. As the whole lake is 4500m^2, in a 750m^2 section, there will be an extra 6 ducks, as 750m^2 is 1/6th of the total lake, and 1/6th of 36 is 6. Therefore, the ratio we found in a) needs to gain an extra 6 ducks, becomming 36:84:36:30, to get it in the form 6:a:b:c you need to divide all parts by 6 (as 36/6=6 gives the 6 we want for the entry in the ratio).


So would the final answer be
6:14:6:5.3?
Reply 5
Original post by Maths1210
So would the final answer be
6:14:6:5.3?


Why 5.3?
Reply 6
Original post by Maths1210
So would the final answer be
6:14:6:5.3?

I meant 5 on the end.
Reply 7
Original post by AstroST
Why 5.3?


I meant 5.
Reply 8
Original post by Maths1210
I meant 5.


That makes more sense! Yup, I agree
Reply 9
Original post by AstroST
That makes more sense! Yup, I agree


Okay. Thanks.
Reply 10
Original post by Maths1210
Okay. Thanks.


Would you be able to help me with this question as well please?
Write x^(2)+14x +31 in the form (x+a)^(2)-b.

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