If 26 horses or 20 bullocks eat up the fodder in store in 170 days, in what time will 10 horses and 8 bullocks finish the same quantity of fodder?

Let amount eaten by each horse and each bullock in one day be 'h' units and 'b' units respectively.

So Total fodder = Total effciency$$\times$$Total number of days 

$$\Rightarrow$$ Total work =  26$$\times$$h$$\times$$170 = 20$$\times$$b$$\times$$170

$$\Rightarrow$$ b = 1.3h............(1)

The amount of fodder eaten by 10 horses and 8 bullocks in one day = 10h + 8b = 10h + 8(1.3h) = 20.4h

Time taken by them to eat the same amount of fodder = total fodder/amount eaten by them in one day

= $$\frac{ 26\times h\times 170}{20.4h}$$

= 216.67 days