The phrase "of varying difficulty" is correct and can be used in written English.
It is typically used to describe something that has different levels or degrees of difficulty. Example: "The math problems in the textbook were of varying difficulty, with some being easy and others requiring more advanced skills."
In all, the gym has over 100 climbing "problems" of varying difficulty.
THE GREAT OUTDOORS Dozens of hiking trails of varying difficulty zigzag around the area.
Bike tours (from €30) are offered as a matter of course, on the farm's single trail park and on numerous tracks of varying difficulty throughout the mountains.
And near the top of the bluff is Hartshorne Woods Park, which has trails of varying difficulty for hiking or biking.
Standing more than 26 feet high is a column of pure ice, featuring three climbing faces of varying difficulty which are scaled using crampons, ice picks and ropes.
The path is well signposted, and is divided into 30km stretches of varying difficulty: most challenging is the hike through the Serra de Monchique, the region's highest point.
Developer King's Candy Crush Saga, which has been downloaded more than 500 million times by mobile users, boasts over 400 levels of varying difficulties where players match up three sweets or treats of the same design or colour, with big rewards for combos and high scores.
It's deliriously simple, and clicks from the first turn – but as I flicked through levels of varying difficulties, acing some immediately and having to repeat others to even register a slow time (attempts are instantly reset with the pressing of a button), I couldn't tear my eyes away from the screen.
It's deliriously simple, and clicks from the first turn but as I flicked through levels of varying difficulties, acing some immediately and having to repeat others to even register a slow time (attempts are instantly reset with the pressing of a button), I couldn't tear my eyes away from the screen.
The selection of two-parameter models in study 2 is in accordance with the literature on the analysis of instruments containing items of widely varying difficulty (DeMars, 2010, Laros, 2005).
Previous experiments investigating the interaction between attention and motor control and learning have commonly employed data-limited secondary tasks [11], [17], [18], [25], [26] or the decision-limited secondary task was of unknown varying difficulty [15], [16].
