Question

Noah spent some of his allowance on Monday. He spent 1/6 of his allowance on Tuesday and 3/6 of it on Friday. Noah has none of his allowance money left. What fraction of his allowance did he spend on Monday?

Answer 1

Noah spent 2/6 of it on Monday.

Answer 2

Let us represent the allowance spent by Noah on Monday by the letter "x".

We know that all the fractions must always add up to 1 in such questions.

Thus, if Noah spent 1/6 of his allowance on Tuesday and 3/6 of it on Friday and he spend x amount on Monday, then these spendings must add up to 1.

In other words,

`x+(1)/(6)+(3)/(6)=1`

`x+(1+3)/(6)=1`

Thus,
`x+(4)/(6)=1`

`\therefore x=1-(4)/(6)=(6-4)/(6)=(2)/(6)=(1)/(3)`

Thus Noah spent a third or
`(1)/(3)` of her allowance on Monday.