Amit and Raman started travelling together in the same direction at 23 km/hr and 35 km/hr receptively. After 10 hours, Amit increased his speed by 13 km/hr and Raman reduced his speed by 15 km/hr, and reached the destination together. How long the entire journey last?
(a) 7 ½ hrs
(b) 17 ½ hrs
(c) 12 1/3 hrs
(d) 15 1/7 hrs
Sol:
A R
23 35
Distance between them = (35–23) × 10 = 120 km