Samia started running towards dhaka from chittagong at a constant speed. At same time, Tanzia started running towards Chittagong from Dhaka at a constant speed. After they crossed each other, it took Samia 40 minutes to reach Dhaka, and it took Tanzia 90 minutes to reach Chittagong. What is the ratio of Samia's speed to Tanzia's speed?

let speed of samia = x km/hr

speed of tanzia = y km/hr

distance = d

time taken to meet = t

distance by samia = xt

distance by tanzia = yt

=> (x+y)t = d

(d-xt) = 2x/3

(d-yt) = 3y/2

2d - (x+y)t = 2x/3 + 3y/2

=> (x+y)t = (4x+9y)/6

(y-x)t = (4x-9y)/6

=> (x+y)/(y-x) = (4x+9y)/(4x-9y)

=> (2x)/(2y) = (18y)/(8x)

=> (x/y)^2 = 9/4

=> (x/y) = 3/2