You can think about the problem like this: (6*1) + (6*(3/4)).
We know that 6*1=6. To do (6*(3/4)), simply multiply the numerator, 3, by 6. This gives you 18/4. The answer will be 6+(18/4), so you must simplify 18/4. 4 goes into 18 four times, so it is equal to 4 and 2/4.
6+4 and 2/4 is equal to 10 and 2/4, so 10 and a half is your answer (10.5).