Rose ran 2 1/4 miles, Jane ran 2 3/8 miles, and Sarah ran 2 7/10 miles. How many miles did the three girls run altogether? A. 6 7/10 miles B. 6 15/40 miles C. 7 13/40 miles D. 8 3/40 miles

C

Step-by-step explanation:

first, make them all have common denominators, which in this case the common denominator would be 40. whatever number you multiply the denominator by to get 40, multiply the numerator by the same number.

for example, for 2 1/4 you'd multiply the denominator by 10 to get 40, so you'd also multiply the numerator by 10, so you'd get 2 10/40.

Rose ran: 2 10/40 miles,

Jane ran 2 15/40 miles,

Sarah ran 2 28/40 miles.

then, you can add, and you'll get 6 53/40 miles, which is 7 13/40 miles.

C.

( ͡° ͜ʖ ͡° ) copy and   paste it

step-by-step explanation:

it's equivalent, so we can say that its equal.

let's call the denominator x and the numerador is 18 less then denominator, x - 18.

multiply

2.x = 5.(x - 18)

2x = 5x - 90

90 = 5x - 2x

90 = 3x

x = 90/3

x = 30

so: