21.
company A
$132 / 1200 = 0.11 cents per minute
company B
$260 / 2000 = 0.13 cents per minute
company A is 2 cents cheaper
answer
3. Company A by 2 cents per minute
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22.
ratio 7:10
so 7 + 10 = 17
357 / 17 = 21
boys to girls 7:10
so
boys = 7 x 21 = 147
girls = 10 x 21 = 210
asking for # of girls
so answer is
1. 210