For it to double its price the price has to be +100% more, and every year you get +2.4%, so you do:
100/2.4≈ 42 years or 41.66666667.. years.
I think you can solve it by
=(x^2 - y^2) *( x^2 + y^2)
= (x -y)*(x+y)*(x^2 + y^2)
David can read 50 pages in 50 minutes.
(50 pages)/(50 minutes) = 1 page/minute
Since David reads 1 page per minute,
in 80 minutes David can read 80 pages.
1) X=159
2) BCD=103
3) DCH=89
im pretty sure
