I need help with PromQL - not sure if this is even possible

Hi there and thanks for opening this post!

I have 3 metrics: sli_1, sli_2 and sli_3. Each metric has a value of either 0 or 1 and is published to Prometheus every minute. What I want is a Singlestat panel that tells me the percentage of time during the past day that the sum of sli_1,. sli_2 and sli_3 had the value of 3.

I’m pretty new to Grafana and PromQL and any help with this query would be greatly appreciated!