How can i solve this formula

K2 Cr2 O7 is the empirical formula

Explanation:

Assume we have 100 g of the compound, because it makes the number of grams equal to the percentage.

Then convert grams of each element into moles

Then divide the moles of each element by the smallest number of moles attained to get the whole number mole ratios of the empirical formula

However, if you don't get whole numbers when you divide by the smallest number of moles, then multiply all moles by one common factor that  makes them all whole numbers.

tracks, burrows, eggshells, nests, tooth marks, or gastroliths