(2) Let number of brown socks = p Let price of brown socks = Rs. s per pair So, price of black socks = Rs. 2s per pair Price before interchanging was (4s + p × 2s) Price after interchanging becomes (4 × 2s + sp) Now, 4s+p×2s=
150
100
(4×2s+sp) 8+4p=24+3p p=24−8=16 Ratio of black socks to brown socks = 4 : 16 = 1 : 4