The second purchase is exactly half-again larger than the first purchase, so sheds no light on the relative costs of the items. The per-item costs can be found when the ratio of items purchased is different from one buy to another.
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We can only say that the cost of 1 pear and 3 apples is $7.
Or if you want to do it the long way you can calculate the actual discount (your savings from this purchase first then subtract it from the original price of $84. It`s just easier to figure out what is left (which is 70% of $84).
