a movie buff buys movies on dvd and on blu - ray in a ratio of 13 : 4 . if she returns 2 blu - ray movies , that ratio would change to 7 : 2 . if she buys movies on no other medium , what was the original number of movies purchased ?
"now coming to the process m ( d ) = 13 x and b ( d ) = 4 x now from the next line the new eqn becomes 13 x / ( 4 x - 2 ) = 7 / 2 solving it 26 x = 28 x - 14 x = 7 which means m ( d ) = 91 and b ( d ) = 28 so total initially is m ( d ) + b ( d ) = 119 e"
multiply(divide(multiply(4, 7), 2), add(13, 4))