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
=
[ 2a + (n - 1)d ], hence
=
[ (2 × 20) + (6 × 3) ]
= 3.5 ( 40 + 18) = 3.5 × 58 = 203