Question

Uthu had some $10 notes and some $2 notes in the ratio of 7:3. He exchanged 6 of his $10 notes into $2 notes. In the end he had the same number of $10 notes and $2 notes. How much money did he have at first?

Answer 1

Uthu had `$684`.

Explanation:

Let Uthu has `7x` number of `$10` notes and `3x` number of `$2` notes,

their value is `7x xx10+3x xx2=70x+6x=76x`

If `6` notes of `$10` are exchanged into `$2` notes, he will get `30` notes of `$2` denominations

and their number becomes `7x-6` for `$10` and `3x+30` for `$2` notes

and then `7x-6=3x+30`

or `7x-3x=30+6` or `4x=36` and `x=9`

So Uthu had `63` number of `$10` notes and `27` number of `$2` notes i.e. `76xx9=$684`