jeremy paid 25.60 for 4 boxes of chocolates this can be expressed using the equation y=kx how much would it have cost jeremy if he bought 10 boxes?

From the expression, the price is directly proportional to the boxes with k being the constant. therefore he bought 4 boxes for 25.6 having the initial constant to be 6.4

if he bought 10 boxes having a constant of 6.4 it becomes y=6.4*10 which becomes 64.