Efficiency of carnot heat engine,if source temperature is T1K and sink temperature is T2K

The efficiency of Carnot engine when source temperature is T 1 and sink temperature is T 2 will be

The efficiency of a carnot heat engine is 0.6 when the absolute temperatures of the source and sink are T_(1) and T_(2) respectively. The efficiency of another carnot engine is also 0.6 but the source and sink temperatures are different. What are the temperatures of the source and the sink of the other engine ?

What percentage T_(1) is of T_(2) for a 10% efficiency of a heat engine? T_(1) is the temperature of sink and T_(2) is the temperature of heat reservoir.

The efficiency of a Carnot's engine at a particular source and sink temperature is (1)/(2) .When the sink temperature is reduced by 100^(@)C , the engine efficiency, becomes (2)/(3) . Find the source temperature.

The efficiency of carnot engine is 50% and temperature of sink is 500K. If temperature of source is kept constant and its efficiency raised to 60%, then the required temperature of the sink will be : -