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PLEASE HELP RIGHT AWAY

PLEASE HELP RIGHT AWAY-example-1
User Lkessler
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1 Answer

7 votes

Answer:

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

User Sam Wilder
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5.0k points