A man lent a sum to his friend at the rate of 9 12 % p.a. After 4 years 6 months, his friends paid him Rs. 20000 and clear the debt, what sum did the man lend to his friend?

33W

$450-$120 to get the difference of their savings

witch is $330 then you subtract the additional money being added each week which is $40-$30 equals to $10 difference so in order for their accounts to balance you divide the $330 by the $10 difference which will be 33 now that will mean that in 33 weeks their account will be balanced