SOLUTION: Please help me with a simple solution. Help for Primary 5 maths. 14 years ago, when Mina celebrated her birthday with her family, the ratio of the age of Mina to Mina's sister was

Algebra.Com
Question 969428: Please help me with a simple solution. Help for Primary 5 maths.
14 years ago, when Mina celebrated her birthday with her family, the ratio of the age of Mina to Mina's sister was 7:9. This year, the ratio of the age of Mina to Mina's sister is 7:8. How old is Mina now?

Answer by Boreal(15235)   (Show Source): You can put this solution on YOUR website!
The ratio of their ages now is 7x/8x, so we need to find x
14 years ago ( 7x-14)/(8x-14) the ratio was 7/9
This is a proportion problem solved with cross multiplication.
(7x-14) *9=(8x-14) *7
Distribute
63x-126=56x -98
solve by first moving the x over, subtracting 56x from both sides
7x-126=-98
add 126 to both sides
7x=28
x=4
The ratio is 7x/8x, so Mina is 28. That is the answer asked for.
Her sister is now 32
14 years ago, Mina was 14 and her sister 18. That is a 7:9 ratio.

RELATED QUESTIONS

10 years ago, when Su Lin celebrated her birthday with her family, the ratio of the age... (answered by mananth,josgarithmetic)
Can you please help me with the solution to this question? Theresa's mom is making her (answered by ankor@dixie-net.com)
Can you please help me with this problem? "Six years ago, Josie was 5 times as old as her (answered by Theo)
Kaye has an arrangement with her father where he pays her $5 for every maths test she... (answered by mananth)
please help me with this question, Tina is 12 years old. Her mom is... (answered by Paul)
Hello, may your please help me on this problem? Sandra is Y years old . In 14 years... (answered by jim_thompson5910,josmiceli)
You just celebrated your child’s first birthday. You decide that you want the best... (answered by Boreal,ikleyn)
The present age of Romila is one-fourth that of her father. After 6 years the father’s... (answered by macston)
Trying to help my daughter with her maths but it's been a long time! Pythagoras theory. (answered by Fombitz)