to make the total large as possible,the large digits should have place value as large as possible.that is , 9 and 8 will be in the tens positions of the two numbers.

Thẹn 3 and 2 will be in thẻ units positions.

then the sum is either  93 + 82 = 175 or 92 + 83 = 175,both with total 175

alternative 1

in cents, 500 : 8 = 6r20 so that he buys 6 chocolates and has 20 cents left

alternative 2

multiples of 80,60, 240,320,400,480,560.from this,he can afford 6 chocolates but not 7