Kaitlin purchased a prepaid phone card for $30. Long distance calls cost 14 cents a minute using this card. Kaitlin used her card only once to make a long distance call. If the remaining credit on her card is $27.90, how many minutes did her call last?

Subtract to find out how much she spent:

30 - 27.90 = 2.10

Divide that by the cost per minute:

2.10 / 0.14 = 15

The call was 15 minutes.

assuming you mean addition: addition and subtraction are reverse operations.

step-by-step explanation:

b. an equilateral triangle inscribed in a circle

step-by-step explanation:

we are given the figure of two circles having a triangle inside.

now, we know that,

"when a figure is lying inside an another figure, then the outside figure is known as circumscribed figure and the figure lying inside is referred to as the inscribed figure".

as we see that, the circles are containing the triangle completely.

thus, the circles are the circumscribed figures and the triangle is the inscribed figure.

hence, we get, 'an equilateral triangle is inscribed in a circle'.