$\mathrm{X}$ bullocks and $\mathrm{Y}$ tractors take 8 days to plough a field. If we halve the number of bullocks and double the number of tractors, it takes 5 days to plough the same field. How many days will it take $\mathrm{X}$ bullocks alone to plough the field?
(A) 30
(B) 35
(C) 40
(D) 45
$\mathrm{X}$ bullocks and $\mathrm{Y}$ tractors take 8 days to plough a field. If we halve the number of bullocks and double the number of tractors, it takes 5 days to plough the same field. How many days will it take $\mathrm{X}$ bullocks alone to plough the field?
(A) 30
(B) 35
(C) 40
(D) 45