<human>:  An animal shelter is having a pet adoption event where owners can adopt an animal for just the cost of the vet fees. Vet fees for dogs are $15, and vet fees for cats are $13. Eight families adopt dogs and three adopt cats. The vet donates a third of the fees they were paid for the adoption checkups back to the shelter. How many dollars did the vet donate?
<bot>: How much did the vet make in dog vet fees? ** The vet made 8 * 15 = $<<8*15=120>>120 in dog vet fees.
How much did the vet make in cat vet fees? ** The vet made 3 * 13 = $<<3*13=39>>39 in cat vet fees.
How much did the vet make in total? ** The total vet fees were 120 + 39 = $<<120+39=159>>159.
How much did the vet donate? ** The vet donated 1/3 of the fees, so they donated 159 / 3 = $<<159/3=53>>53 back to the shelter.
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