0000:00:00:00:00Start4Number 4ExplanationA train travels the distance from Jakarta to Surabaya at a speed of 606060 km/h for 151515 hours. If this distance is to be covered in 121212 hours, the speed of the train becomes...858585 km/h959595 km/h808080 km/h757575 km/h909090 km/hExplanationThis problem is an example of inverse proportion, where the distance traveled remains constant. Given: v1=60 km/hv_1 = 60\ \text{km/h}v1=60 km/ht1=15 hourst_1 = 15\ \text{hours}t1=15 hourst2=12 hourst_2 = 12\ \text{hours}t2=12 hours We use the distance formula S=v×tS = v \times tS=v×t: S1=S2S_1 = S_2S1=S2v1×t1=v2×t2v_1 \times t_1 = v_2 \times t_2v1×t1=v2×t260×15=v2×1260 \times 15 = v_2 \times 1260×15=v2×12900=12v2900 = 12 v_2900=12v2v2=90012v_2 = \frac{900}{12}v2=12900v2=75 km/hv_2 = 75\ \text{km/h}v2=75 km/h Thus, the speed of the train becomes 757575 km/h.
4Number 4ExplanationA train travels the distance from Jakarta to Surabaya at a speed of 606060 km/h for 151515 hours. If this distance is to be covered in 121212 hours, the speed of the train becomes...858585 km/h959595 km/h808080 km/h757575 km/h909090 km/hExplanationThis problem is an example of inverse proportion, where the distance traveled remains constant. Given: v1=60 km/hv_1 = 60\ \text{km/h}v1=60 km/ht1=15 hourst_1 = 15\ \text{hours}t1=15 hourst2=12 hourst_2 = 12\ \text{hours}t2=12 hours We use the distance formula S=v×tS = v \times tS=v×t: S1=S2S_1 = S_2S1=S2v1×t1=v2×t2v_1 \times t_1 = v_2 \times t_2v1×t1=v2×t260×15=v2×1260 \times 15 = v_2 \times 1260×15=v2×12900=12v2900 = 12 v_2900=12v2v2=90012v_2 = \frac{900}{12}v2=12900v2=75 km/hv_2 = 75\ \text{km/h}v2=75 km/h Thus, the speed of the train becomes 757575 km/h.
