From a base elevation of 8400 ft, a mountain peak in colorado rises to a summit elevation of 14831 ft over a horizontal distance of 15836 ft. find the grade of the peak.

There are no mountain peaks in Colorado that are that high, but I will play along anyway.

The grade is the elevation change, divided by the horizontal distance, expressed as a percentage. That would be
(14831-8400)/15836. Do the numbers.