(7/2+a)²+(7/2+a+x)²=7²-----(1) (7/2+a-x)²+a²=(7/2)²-----(2) Find values of a and x ?

In 1996 it will be 42.666 after 4 years ie in 2000 it will be 42.666+4 = 46.666

Let earlier speed is 4 now it becomes 3 So time ratio becomes 3:4, difference 1x=>2.5 Actual i.e,3x=7.5

16 ,b , c are in A.P so b=(c+16)/2 c=2b-16......................(1) 16 , b+3, c+15 are in G.p (b+3)^2= 16(15+c) putting value of c from (1) b^2+9+6...

Let reduction=R and no. Of bogies be n R=k×n^2 60= k×36 K= 5/3 Now 120= 5/3× N^2 N=√72 N=8.5 So max no. Of bogies it can carry is 8