The major mistake that students make while preparing for examinations like JAMB is that they do not consider important materials like the syllabus The syllabus contains the list of topics that are expected to be covered by the candidates before the examination. However, examination bodies like JAMB and WAEC provide explicit details on what to expect for the examination. I can tell you for sure that you can score very high in JAMB without the use of past questions I know one of my students who only faced the syllabus squarely and he ended up scoring 310 in JAMB.
I will be sharing the list of topics that JAMB test candidates on. The list below are the topics that JAMB must test candidates on.

Number bases
Fractions, Decimals, Approximations and Percentages
Indices, Logarithms and Surds
Sets
Polynomials
Variation
Inequalities
Progression
Binary Operations
Matrices and Determinants
Euclidean Geometry
Mensuration
Loci
Coordinate Geometry
Trigonometry
Differentiation
Application of differentiation
Integration
Representation of data
Measures of Location
Measures of Dispersion
Permutation and Combination
Probability
You can see the detailed syllabus [https://acadaace.com/mathematics-syllabus-jamb-2024/]HERE[/https://acadaace.com/mathematics-syllabus-jamb-2024/]