Question

The ratio of a to b is 3 to 1, and the ratio of b to c is 1 to 5. What is the value of 2a+3b/ 4b+3c?

A. 3/16
B. 9/19
C. 1/2
D. 5/7
E. 18/19

Answer 1

B

Explanation:

Expressing the ratios as fractions, that is

`(a)/(b)` =
`(3)/(1)` ( cross- multiply )

a = 3b

`(b)/(c)` =
`(1)/(5)` ( cross- multiply )

c = 5b

------------------------------------------

Given

`(2a+3b)/(4b+3c)` , substitute values from above for a and c

=
`(2(3b)+3b)/(4b+3(5b))`

=
`(6b+3b)/(4b+15b)`

=
`(9b)/(19b)` ← cancel b on numerator/ denominator

=
`(9)/(19)` → B