A mother is now 2 1/2 times old as her daughter Mary. Four years ago the ratio of their ages was 3:1. Find the present age of the mother.

The present age of the mother is 40 years

Step-by-step explanation:

Let the age of the mother be M and that of the daughter D. Given that the mother is now 2 1/2 times old as her daughter Mary then

M = 2.5D

Given that Four years ago the ratio of their ages was 3:1

The mother's age 4 years ago was

= M - 4

and that of the daughter then was

= D - 4

Hence

(M - 4)/(D - 4) = 3/1

Cross multiply

M - 4 = 3(D - 4)

M - 4  = 3D - 12

M = 3D - 12 + 4

M = 3D - 8

Substitute into the first equation

3D - 8 = 2.5D

3D -2.5D = 8

0.5D = 8

D = 8/0.5

= 16 Years

M = 2.5D

M = 2.5 * 16

= 40 Years

3/4 ÷ 3/4

step-by-step explanation:

basically divide any proper fraction with itself to fit the criteria.

so if we are using 3/4, then:

3/4 ÷ 3/4 = 1

so 1 is the quotient.

and the numerators for both these fractions is 3.   and if we divide the numerators:

3 ÷ 3 = 1

we see that quotient is equal to our original quotient as well.

the correct answers i think are b. and d.

give me brainliest if it is correct!