7. In order to cater to customers' psychology, a mall bundles two items with different cost prices for sale. Both items are sold for 216 yuan, with one item at a loss of $20 \%$, but the overall profit is $20 \%$. The cost price of the other item should be $\qquad$ yuan.
7. 90 .

Let the cost price of the other item be $x$ yuan, $216 \div(1-20 \%)=270$ (yuan), $(270+x)(1+20 \%)=216 \times 2$, $x=90$.