Let Principal Borrowed by A and B = x
Formula for S.I = (P*T*R) /100 [ let total amount paid by B=y
Therefore, Money paid by A=550+y]
Amount = P+SI
Solution for A
SI = (x*8*4)/100
Amount = P+SI
550+y = x+32x /100 --------------------(i)
Solution for B
Amount =P+SI
y = x + 22x /100 -----------------------(ii)
Substituting the value of y in equation (i)
550 + x +22x/100 = x + 32x /100
550 = 10x/100
x = $ 5500-----------[Answer]