4. (6 points) A food store sold a total of 100 kilograms of three types of candy priced at 20 yuan, 25 yuan, and 30 yuan per kilogram, earning a total of 2570 yuan. It is known that the total income from selling the 25 yuan per kilogram and 30 yuan per kilogram candies was 1970 yuan. The 25 yuan per kilogram candy was sold for $\qquad$ kilograms.

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4. (6 points) A food store sold a total of 100 kilograms of three types of candy priced at 20 yuan, 25 yuan, and 30 yuan per kilogram, earning a total of 2570 yuan. It is known that the total income from selling the 25 yuan per kilogram and 30 yuan per kilogram candies was 1970 yuan. The 25 yuan per kilogram candy was sold for 26 kilograms.
【Solution】Solution: $100-(2570-1970) \div 20$,
$$
\begin{aligned}
= & 100-30, \\
= & 70 \text { (kilograms); } \\
& (30 \times 70-1970) \div(30-25), \\
= & 130 \div 5, \\
= & 26 \text { (kilograms); }
\end{aligned}
$$

Answer: The 25 yuan per kilogram candy was actually sold for 26 kilograms;
Therefore, the answer is: 26.