Question

Mathew has received $1 the first week, $3 the 2nd week, $5 the 3rd week and so on until he has received a total of
$1 000 000. What amount did he receive the last week?

Answer 1

looks like an arithmetic series where
a = 1 , d = 2, n = ?
Sum(n) = 1000000

(n/2)(2 + (n-1)(2) ) = 1000000
n( 2 + 2n - 2) = 2000000
2n^2 = 2000000
n^2 = 1000000
n = 1000

so term (1000) = a + 999d = 1 + 2(999) = 1999