Calculating reactions forces of pillars

Question

I have the question "A uniform bridge of mass 10 000 kg and length 60m rests on two narrow pillars at its ends. A lorry of mass 1500 kg is situated one-quarter of the way across the bridge.

Calculate the reaction forces of the pillars when the lorry is exactly one-quarter of the way across the bridge.

Here is my attempt:

So I get 52.7 KN for the pillar on the far left and 60.1 KN for the pillar on the far right.

However the solutions say that it should be 54 KN and 61 KN what have I done wrong ?

Answer 1

There are two things that you did, that are more correct than the given solution. 1. Use $g=10m/s^2$. 2.Ignore everything after the decimal point. That way $S=53.75 kN\approx 54 kN$ and then $R=115kN-54kN=61kN$