Simple interest formula I = P x R x T where
P is the Principal amount of money to be invested at an Interest Rate R% per period for T Number of Time Periods.
Interests accrued by Saurabh in 2007 from company A = 12000 x 15 x 1/100
Interests accrued by Saurabh in 2007 from company B = 15000 x 14 x 1/100
Total interests accrued by Saurabh in 2007 from company A and company B = ( 12000 x 15 x 1/100 ) + (15000 x 14 x 1/100 )
Total interests accrued by Saurabh in 2007 from company A and company B = ( 120 x 15 ) + (150 x 14 )
Total interests accrued by Saurabh in 2007 from company A and company B = 1800 + 2100
Total interests accrued by Saurabh in 2007 from company A and company B = Rs. 3900