How is let-7 related to miR-98?

[TytoAlba95]

Hi. I have been recently introduced to a website called targetscan which is both a database and a tool to discover recorded miRNA-target gene interactions.
I'm stuck with some questions.
For TargetScanMouse, when Hmga2 gene is used as the query/input, a number of miRNAs come out. If I choose let-7 from this link it can be seen that let-7/miR-98 have been mentioned together. Why are they together? let-7 is a microRNA precursor, so is miR-98 its product miRNA?
Also multiple miRNAs are written together, for e.g. miR-15-5p/16-5p/195-5p/322-5p/497-5p, displayed at the middle bottom. Are they synonyms?

 

[Ygggdrasil]

let-7/miR-98 does not refer to a single miRNA, but a family of related miRNAs that all target similar sequences:

https://www.sciencedirect.com/science/article/pii/S0962892408002109

Other miRNAs are also part of miRNA families that target similar sequences, so they will often be identified together as targeting the same sets of genes.