Business math problem

You decide to put away 200 EUR every month. Bank A offers simple interest of 6 per
cent per annum, and bank B offers 0.48 per cent per month compounded monthly.
After making 12 deposits, how much money would you have at the end of one year
in banks A and B, respectively? (a) The deposits are made at the same time the interest is credited (i.e. at the end of
each month).
(b) The deposits are made at the beginning of each month and the interest is credited at the end.
I want a detailed solution for bank A Q a) has to be "2466 EUR" and for b) 2478

as requested, solution for bank A

(a) I = 200*(6/1200)(11+10+9+8+..... +0) = 200*.005*66 = 66
[ 11 months interest on 1st deposit, 10 on 2nd, ... 0 on last ]
A = P+I = 200*12 + 66 = 2466 <----------

(b) I = 200*(6/1200)(12+11+10+ .... +1) = 200*.005*78 = 78
[ 12 months interest on 1st deposit, 11 on 2nd, ..... 1 on last ]
A = P+I = 200*12 + 78 = 2478 <---------

note:
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use formula 1+2+3+.... n = n(n+1)/2 for computing total mths of interest

business math is the dullest application of mathematics

thank you for sharing this