Let the price of the item be t as stated in the question.
This means if Top quality is selling them at 15% off the list price, then the new price can be represented as;
(A)
(B)
Equation 1 shows the original list price less the discounted amount (which is 15 percent times the list price, t). The result is the price now paid eventually
Equation 2 shows the percentage of the list price that would be paid by Jenna after deducting the discount, which means she would be paying 85 percent of the list price (that is 0.85)
(C)
A smartphone on sale at 1/4 off its list price, would also mean its being sold at a discount of 25%. One-quarters of 100 percent would be 25, hence the smartphone is at 25% off the list price.
However, where the phone is being sold at 75% of its list price means, the list price now has 25% taken off. That is, the price at Big Value is
That means the discount at Big value is 25% (or 0.25)
The discount at Top Quality is 25% (0.25 or 1/4)
Jenna can buy at either of the store. Since she is already at Top Quality, she can just go ahead and buy it right there