Correct Answer - B
`{:("Milk",:,,"water"),("Initial",7,:,5),("final",7,:,8):}`
Adding 15 litre water (15 लीटर पानी मिलाने पर)
`(7x)/(5x+15)=(7)/(8)`
`8x=5x+15`
`x=(15)/(3)`
`x=5`
`:.` At present (वर्तमान में) = milk : water = 7x : 8x
water `=8x =8 xx 5 = 40` litr