Answers by visitors named: Sajal

Total Time taken t= distance / average speed=60/40=1.5h Time taken to cover first half T1=30/30=1h Time taken to cover second half T2=30/V Now,T=T1+T2=1.5=1+30/V Then,1.5V=1V+30 30=1.5V-1V 30=0.5V 30/0.5=V Hence,V=60kmh

Part(a) Base of square =12cm Slant height of pyramid =15cm [Applying the theorem] (Height)^2+6^2=15^2 (Height)^2=225-36 (Height)^2=189 Height=189^2 Height= (square root of189) = 13.74cm Part(b). :. volume of pyram =1/3×base area×h Volume of pyramid =1/3×12^2×13.74cm^3 =659.52cm^3