Question 1057578
 A solution contains 77 milliliters of HCl and 143 milliliters of water.
 If another solution is to have the same concentration of HCl in water but is to contain 91 milliliters of water, how much HCl must it contain? 
:
let h = amt of HCl required
{{{h/91}}} = {{{77/143}}}
cross multiply 
143h = 91*77
h = {{{7007/143}}}
h = 49 ml of HCL