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Can't understand how to do reverse fractions

Hi :smile:.

I am stuck on a way on how to solve the below style questions.

A number is decreased by 1/4 to 21. What was the number?

A number is increased by 2/5 to 49. What was the number?

What is the method to solving questions like these?

Thanks
Original post by marcus888
Hi :smile:.

I am stuck on a way on how to solve the below style questions.

A number is decreased by 1/4 to 21. What was the number?

A number is increased by 2/5 to 49. What was the number?

What is the method to solving questions like these?

Thanks



Set up equations and solve for the variables.

a14a=21a-\frac{1}{4}a=21

b+25b=49b+\frac{2}{5}b=49

Although I do not like the wording there, when it says "decreased by 1/4 to 21" it could just mean c0.25=21c-0.25=21, so be wary of this.
(edited 7 years ago)
Reply 2
Original post by RDKGames
Set up equations and solve for the variables.

a14a=21a-\frac{1}{4}a=21

b+25b=49b+\frac{2}{5}b=49

Although I do not like the wording there, when it says "decreased by 1/4 to 21" it could just mean c0.25=21c-0.25=21, so be wary of this.


Ah thanks

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