Two places P and Q are 440 km apart. Anuj starts from point P towards Q and Dia starts from point Q towards P and they meet after 8 hours. After meeting, Anuj decreased his speed by 9 km/hr and Dia increased her speed by 9 km/hr, then they reached their respective destination at the same time. What is the initial speed of Dia?
Two places P and Q are 440 km apart. Anuj starts from point P towards Q and Dia starts from point Q towards P and they meet after 8 hours. After meeting, Anuj decreased his speed by 9 km/hr and Dia increased her speed by 9 km/hr, then they reached their respective destination at the same time. What is the initial speed of Dia? Correct Answer 23 km/hr
Since Anuj and Dia are travelling towards each other, the relative speed must be the sum of the speed of Anuj and Dia;
Suppose the speeds of Anuj and Dia are ‘A’ and ‘D’ km/hr respectively;
∴ (A + D) = 440/8
⇒ (A + D) = 55 ---- (1)
After meeting, Anuj decreased his speed by 9 km/hr and Dia increased her speed by 9 km/hr then they reached their respective destination at the same time;
This is possible only if the new speed of Anuj becomes equal to the initial speed of Dia and vice versa.
∴ (A - D) = 9 ---- (2)
Solving both the equations∶
⇒ A = 32 and B = 23
∴ Initial speed of Dia = 23 km/hr