Let S be the reflection of a point Q with respect to the plane given by r=−(t+p)î+tĵ+(1+p)k^, where t,p are real parameters and î,ĵ,k^ are the unit vectors along the three positive coordinate axes. If the position vectors of Q and S are 10î+15ĵ+20k^ and αî+βĵ+γk^ respectively, then which of the following is/are TRUE?