Question

Four cars are hired at the rate of Rs.6 per km plus the cost of diesel at Rs. 40 a litre. In this context,

Answer 1

Let the distances travelled by cars A,B,C and D be a,b,c and d respectively.

 Then, total payment for car A = 6a+40(a/8) = 11a=2120 => a=2120/11

It is mentioned that car A travels for 20 hr

=> The average speed of A= a/20 = 2120/11*20 = 106/11 > 9

 Equation for B: 6b+40(b/10)=1950 => b=195

=> The average speed of B= b/25 = 195/25 = 39/5=7.8

Equation for C: 6c+40(c/9)=2064 => c=9*1032/47

=> The average speed of C= c/24 = 9*43/47 < 9

Equation for D: 6d+40(d/11)=1812 => d=11*906/53

=> The average speed of D= d/22 = 453/53 < 9

All speeds except for A are less than 9 where as seed for A is greater than 9 and hence it’s the greatest value.