let

s = the number of calories in one scoop of ice-cream

c = the number of calories in one sugar cone

One scoop of ice cream is 5 times as many calories as a sugar cone

s = 5c

Ken bought a sugar cone with two scoop of ice cream and two scoops and cone together had 495 calories

2s + c = 495

by solving the system of equations

s = 5c

2s + c = 495

we find

c = 45 calories

s = 225 calories

click here to see the step by step solution of the system of equations

once scoop of ice-cream has 225 calories.