Question

If the cost of a telephone conversation varies directly as the length of the time of conversation, and if the cost of six minutes is $0.90, what would be the cost for a nine-minute call?

Answer 1

it would cost $1.35

.9 divided by 6 = .15

.15 times 9 = $1.35

Answer 2

Answer: $1.35

Explanation:

we already know that the cost of six minute calls is equal to $0.90, but we are ask to find the cost for nine minute. To solve this, we will need to use proprtion. Thus;

using proportion,

6 minutes = $0. 90

9 minutes = x

cross multiply

6 × x = 0. 90 × 9

6x = 8. 1

Now, to solve for x, will have to make x subject of the formula, to do that we will divide both-side of the equation by 6

6x/6 = 8.1/6

x = $1. 35

Therefore the cost for a nine- minute call is $1. 35