In the first month, she made a payment of $1451
In the second month, she paid one-third of that, which amounts to:
1451/3 = 483.66
For the third month, she pays one-third of 483.66 as indicated, meaning she takes one-third of the prior month's payment.
483.66/3 = 161.22
In the fourth month, her payment was
161.22/3 = 53.74
Altogether, her total payments amounted to:
$2149.62 - B.
Hope this information is helpful:)
Because SI units are structured around powers of 10, you can shift the decimal point to convert; imperial units lack that base-10 organization, so the decimal-shifting method doesn't apply.