A & B share the cost in a ratio of 7:2. A pays £126, how much does B pay?

2 Answers
Jim G.
Jul 10, 2016

₤ 36

Explanation:

The sum of the 'parts' of the ratio = 7 + 2 = 9

Of which A pays 7 of the parts and B, 2 of the parts.

Since A pays 7 parts then 1 part = ₤126 ÷ 7 = £18

Hence 2parts =2xx£18=£36

Thus B pays £36

As a check : Total paid = £126 + £36 = £162

and £162 ÷ 9 = £18

Tony B
Jul 11, 2016

B pays £36.00

Explanation:

Using ratio in the format of a fraction.

("Payment by A")/("Payment by B") =7/2=(£126)/B

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Turning it upside down (makes it easier to determine B)

2/7=B/126

color(white)(.)
,........................................................
Multiply both sides by color(blue)(126)

color(brown)(2/7color(blue)(xx126)" "=" "B/126color(blue)(126))

color(white)(.)

252/7" "=" "Bxx126/126

,.............................................................
color(white)(.)

But 126/126=1 " so "Bxx1 = B giving:

color(white)(.)

B=252/7 = 36

B pays £36.00

Related questions
See all questions in Ratios and Proportions
Impact of this question
6249 views around the world
You can reuse this answer
Creative Commons License