If a/b = 2/3 and b/c = 4/5, then (a+b)/(b+c) is:

'b' को समान करें: a:b = 8:12, b:c = 12:15। तो a=8, b=12, c=15। (a+b)/(b+c) = (8+12)/(12+15) = 20/27।