You just have to turn two of them into either a fraction, decimal, or percentage. Let's just make them all decimals for this problem.
40% as a decimal is 0.4 (You divide percentages by 100 to get the decimal equivalent).
1/4 as a fraction is 0.25 (How I remember 1/4 as a decimal is that one quarter is 25, two is 50, three is 75, and four is 100. For anything else, you usually have to long divide.)
So, now we have 0.3 + 0.4 + 0.25
If you add all three of those together, you get 0.95