Thelma spent 1/6 of her weekly allowance on dog toys. 1/4 on a dog collar and 1/3 on dog food. what fraction of her weekly allowance is left

First you have to find a common denominator, in this case it's 12.
Then change the fractions to equivalent fractions.
1/6= 2/12
1/4= 3/12
1/3= 4/12
Then add all the fractions up and subtract from the denominator, 12: 9/12
And finally, the remainder is 3, or 3/12. (simplified: 1/4)
Hope this helps! :)