## Question

primary 5 | Maths | Fractions

Anyone can contribute an answer, even non-tutors.

##### Tsl

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Pls help me to understand why the answer is 3 instead of 2.thank you

Date Posted: 5 months ago
Views: 31
Eric Nicholas K
5 months ago
She bought 3/4 kg of sugar and used 1/5 of it

(NOT the same as she bought 3/4 kg of sugar and used 1/5 kg)

1/5 of the 3/4 kg
= 1/5 x 3/4
= 3/20

Mass left
= 3/4 - 3/20
= 15/20 - 3/2
= 12/20
= 3/5
Eric Nicholas K
5 months ago

She bought 3/4 kg sugar and used 1/5 kg of sugar

Then the mass left
= 3/4 - 1/5
= 15/20 - 4/20
= 11/20

The phrase “1/5 of it” versus “1/5 kg” are completely different.
Tsl
5 months ago
Thank you for your explanation, but I still don't get it what is the different between of and of it?
Can you Pls explain more .thank you
Eric Nicholas K
5 months ago
1/5 of it means 1/5 out of the 3/4 kg

This means that we split the 3/4 kg into 5 equal parts. If we express 3/4 kg as 15/20 kg, we can split this into 5 equal parts of 3/20 kg each.

This is different from the other case in which you are just subtracting kg against another kg.
Eric Nicholas K
5 months ago
The difference lies in the word kg.

“1/5 of it” and “1/5 kg of it”.

These are not the same.
Tsl
5 months ago
Understand now.thank you very much.