Question

Mr Toh made tuna and curry potato filling for some puffs.

3/5 of the filling he made was tuna and the rest were curry potato .

After using 1/8kg  of tuna filling and made another 3/4 kg of curry potato filling,

he had equal amount of tuna filling and curry potato filling left.

how much did he make for tuna filling at first?

appreciate any help

Hi Ozora,

For this question, I’ve drawn a model to help explain it.

3/4kg + 1/8kg = 6/8kg +1/8kg =7/8kg

If there are a total of 5u of filling, we know that

1u=7/8kg

3u = 7/8kg x 3 =21/8kg

Expressing the answer in mixed numbers, he made 2(5/8)kg of tuna filling at first.

https://ibb.co/dnJzTb

If this answer helped, please like and accept it to let me know :)!

How do we justify that 1 u is 7/8kg?

i understand the 2 units is curry n 3 units is tuna but I can’t justify the equal amount left for both items.

thanks again

Hi there!

The way we justify 1 unit = 7/8kg is best seen via a model, but let me try my best with words.

We know that when he uses up 1/8kg of tuna filling, he has 2 units of tuna filling + some extra left.

We know that he has 2 units of Curry to begin with, but once he adds 3/4kg more, he has 2 units + some extra.

Since we know he has an equal amount of each filling after adding and subtracting, we must find what is the “some extra” filling left.

To find this, we realise that you must take the 3/4kg added + 1/8kg used up to find one unit.

If it helps, try drawing it out!

Alternatively, you can like us on www.facebook.com/dingletutors and private message me for the picture of the model 🙂

All the best!

-Michelle (www.dingletutors.com)

yes can see the image now.

Thanks . can understand now and explain it to my niece.

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All the best!

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T  :  C  : Total

At first      3  :  2  :  5

-1/8kg  |      | +3/4kg

In the end 1  :  1

3u – 1/8 = 2u + 3/4

(Multiply throughout by 8)

24u – 1 = 16u + 6

24u-16u = 6+1

8u = 7

1u = 7/8

T at first = 7/8 kg × 3

= 21/8 kg

= 2  5/8 kg (ans)

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tuna : 3 units
curry potato : 2 units
3 units – 1/8 kg = 2 units + 3/4 kg
1 unit = 7/8 kg
3 units = 2 5/8 kg

Ans : 2 5/8 kg.

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This is a Before After question.

 Before Transfer After Tuna 3u – 0.125 3u – 0.125 Curry 2u + 0.75 2u + 0.75 Total 5u

3u – 0.125  = 2u + 0.75

3u – 2u = 0.75 + 0.125

1u = 0.875

3u = 0.875 × 3 = 2.625 kg