A total amount of Rs7000 is deposited in three different saving bank accounts with annual interest rates 5%, 8% and 8 1/2% respectively. The total annual interest from these three accounts is 550 RUPEES. Equal amounts have been deposited in the 5% and 8% savings accounts. Find the amount deposited in each of the three accounts using matrix method.

Let the amount deposited in the saving bank account with interest rate 5%=x.Let the amount deposited in the saving bank account with interest rate 8%=y.Let the amount deposited in the saving bank account with interest rate 172%=z.A.T.Qx+y+z=70005100x+8100y+17200z=550x=y   x-y=0These equations can be expressed as AX=B.Where A=11151008100172001-10, X=xyz  and B=70005500A=117200-1-17200+1-13100=17+17-26200=82000So, A is nonsingular matrix and inverse exists.A11=17200  A11=17200   A11=-13100  A11=-1     A11=-1      A11=2  A11=1200   A11=-7200   A11=3100 adj A=17200-1 120017200-1  -7200-13100  2  3100 A-1=1Aadj A=200817200-1 120017200-1  -7200-13100  2  3100X=A-1B=200817200-1 120017200-1  -7200-13100  2  310070005500   =20084545190=9000890008380008=112511254750the amount deposited in the saving bank account with interest rate 5%=Rs.1125.the amount deposited in the saving bank account with interest rate 8%=Rs.1125.Let the amount deposited in the saving bank account with interest rate 172%=Rs.4750.

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