2/3 part of 78/5 can be found by just multiplying 2/3 with 78/5
so that is
(2/3) * (78/5)
to multiply 2 fractions just multiply the numbers on the numerator and set it as the numerator of the result and multiply the denominators of the number and place it in the denominator of the result ie,
(2*78)/(3*5)
156/15
156/15 can be simplified as
156/15=(52*3)/(5*3)=52/5=10.4