Three pastures X, Y and Z have some horses grazing in them.

The ratio of the number of horses in pasture X to the number of horses in pasture Y is 8 : 7.

The ratio of the number of horses in pasture Y to the number of horses in pasture Z is 2 : 3.

Pasture Z has 75 more horses than pasture X.

Find the total number of horses grazing in pastures X and Y.