12, 14, 15, 16 Tolong ya

12.Kpk=90 menit+19.30=1.30+19.30=21.00
14.V=d*w=45 l/m * 2 1/2 j
=45*150=6750 l
15.3 1/4 kg+1/2 kg+4 ons=32,5+5+4=41,5
16.W=900:3=300 detik=50 m

no.15 900/3 = 300
1 menit = 60 detik
300/60 = 5 menit