how to solve this to get exactly same answer?
Answers
Step-by-step explanation:
A's account
Dep 1200 for 36 months. Interest = 1200 × 10% × 36 / 12 = 360
Dep 1200 for 35 months. Interest = 1200 × 10% × 35 / 12 = 350
...
Dep 1200 for 1 month. Interest = 1200 × 10% × 1 / 12 = 10
Deposits total = 36 × 1200 = 43200
Interest total = 10 + 20 + ... + 360 = 10 × ( 1 + 2 + ... + 36 )
= 10 × 36 × 37 / 2 = 6660
Balance = 43200 + 6660 = 49860
B's account
Dep 1500 for 30 months. Interest = 1500 × 10% × 30 / 12 = 375
Dep 1500 for 29 months. Interest = 1500 × 10% × 29 / 12 = 362.50
...
Dep 1500 for 1 month. Interest = 1500 × 10% × 1 / 12 = 12.50
Deposits total = 30 × 1500 = 45000
Interest total = 12.50 × ( 1 + 2 + ... + 30 ) = 12.50 × 30 × 31 / 2 = 5812.50
Balance = 45000 + 5812.50 = 50812.50
Comparison
B's account balance (50812.50) is higher than A's balance (49860) by
50812.50 - 49860 = 952.50