Question

A boy spends 3/4 of his pocket money and then 4/5 of the remainder is given to his sister. if he has Rs 40 left, what did he have at first ?​

Answer 1

Let the pocket money be

=

x

x

−

3

x

4

is amount remaining with him after spending money.

x

−

3

x

4

=

4

x

−

3

x

4

⇒

x

−

3

x

4

=

x

4

Now, he gave

4

5

of remaining amount to his sister.

then the remaining amount is

x

4

−

4

5

×

x

4

=

x

4

−

x

5

=

5

x

−

4

x

20

=

x

20

According to given question remaining amount is

40

Thus,

x

20

=

40

⇒

x

=

40

×

20

∴

x

=

800

His pocket money is

800