how semi compounding works for yearly , P= 100 and interest rate is 10% then for 6 month 5% will be applied thus interest= 5 so
amount after 6 month is 105 and for next 6 month 5% will applied on 105 thus amount =110.25

Two amount 90000 & 30000
for 90000 , total interest rate 2% thus interest for 6 months is 1% thus interest=900
for next 6 month 1% interest thus 1% of 900 = 9 , thus interest=909
now total interest after year = 900+909=1809

Remaining amount = 3636-1809=1827

for 30000 let say x% interest , now solve like above by taking values from option , lets take 6

for 1st 6 months , interest will be 3% = 3% of 30000= 900
for 2nd 6 months ,interest will be 3% = 3% of 900 = 27 thus interest =927
total = 900+927=1827 it matches thus answer is D