21. How many ways are there to put 7 identical oranges into 4 identical packages so that each package has at least one apple?
22. Determine the exact value of
\(\frac{2}{\frac{1}{\sqrt 2 + \sqrt[4]8 +2}+\frac{1}{\sqrt 2 + \sqrt[4]8 – 2}}\)
23. Find the integer which is closests to \(\frac{(1+\sqrt 3)^4}{4}\)
24. Find the 2021th-smallest \(x\) with \(x > 1\), that satisfes the following relation:
\(\sin(\ln x) + 2 \cos(3 \ln x) \sin(2 \ln x) = 0\).
25. A circle is inscribed in a right triangle with sides \(a, b,\) and \(c\), where \(c\) is the hypotenuse, as shown in the diagram. Find the radius of the circle using the sides of the triangle.
Baca juga : Problems And Answers PHIMO MOCK 2020 JUNIOR SECONDARY