Question

PLEASE HELP RIGHT AWAY

Answer 1

203 minutes

Explanation:

This can be expressed as an arithmetic sequence, that is

20, 23, 26, 29,...

With first term a = 20 and common difference d = 3

The sum to n terms of an arithmetic sequence is

`S_(n)` =
`(n)/(2)` [ 2a + (n - 1)d ], hence

`S_(7)` =
`(7)/(2)` [ (2 × 20) + (6 × 3) ]

= 3.5 ( 40 + 18) = 3.5 × 58 = 203