In the U.S. you should be using 110-115V.
76+v+24 = 125 v = 125 -76-24 v = 25
If you live in an area that uses 115V as the mains supply, then it's absolutely fine. Equipment sold in the area will be designed to operate on that voltage and there is no difference in performance between 115V equipment and 230V equipment.
75/125 = 0.6 Ampere
V = 125 cm3
v channels
V = 125 m3
Your electrician is correct on this. However, the pump is designed for 230V and will use less electricity, thus saving money if wired for 230V. Yeah, if you have to rewire for 230 V then it would be more expensive until your savings had consumed or offset the expense.
Volume of a cube (V) = l*w*h V = 5*5*5 = 125 cm3 or 125 cc
125 v
V = 125 m3 All sides are 5m so the product is 5x5x5=125
V = 125 cubic yards.