If Miss tan wants to buy 10 cupcakes, she needs to pay additional $7. But if she buys only 6 cupcakes, she has a balance of $14. How much does each cupcake cost?

solution:

.........<-------------- 10 cakes ------------------->

.........----------------------------------------======

.........|..............................................||...$7....||

.........----------------------------------------======

.........<-------- 6 cakes ----->

.........---------------------------------------

........|.................................|....$14...|

.........---------------------------------------

Thus,

4 cakes cost $(14 + 7) = $21

and so, 1 cake costs $21 / 4 = **$5.25** .....................hmm, very expensive

Check:

so, 6 cupcakes cost $5.25 x 6 = $31.50

which when you add $14, she has $45.50

which is $7 short of $52.50 for 10 cakes