Watch comprehensive video reviews for most units, designed for final exam preparation. Each video includes integrated problems you can solve alongside detailed solutions.
Not your average video:
Interactive Problems: Solve problems alongside the video with step-by-step guidance and detailed solutions.
Exam Preparation: Complete unit reviews designed for final exam preparation with all key concepts covered systematically.
Expert Teaching: High-quality instruction from Perplex co-founder James Mullen with clear explanations, worked examples, and exam tips.
Not your average video:
Interactive Problems: Solve problems alongside the video with step-by-step guidance and detailed solutions.
Exam Preparation: Complete unit reviews designed for final exam preparation with all key concepts covered systematically.
Expert Teaching: High-quality instruction from Perplex co-founder James Mullen with clear explanations, worked examples, and exam tips.
Counting & Binomials
Watch comprehensive video reviews for Counting & Binomials, designed for final exam preparation. Each video includes integrated problems you can solve alongside detailed solutions.
Not your average video:
Interactive Problems: Solve problems alongside the video with step-by-step guidance and detailed solutions.
Exam Preparation: Complete unit reviews designed for final exam preparation with all key concepts covered systematically.
Expert Teaching: High-quality instruction from Perplex co-founder James Mullen with clear explanations, worked examples, and exam tips.
Not your average video:
Interactive Problems: Solve problems alongside the video with step-by-step guidance and detailed solutions.
Exam Preparation: Complete unit reviews designed for final exam preparation with all key concepts covered systematically.
Expert Teaching: High-quality instruction from Perplex co-founder James Mullen with clear explanations, worked examples, and exam tips.
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AHL AA 1.10
How many ways can the items B1,B2,B3,B4,B5 be ordered under the restriction that B1 and B2 must be together.
To solve questions like these, we treat the items that must stay together as a single unit. We consider that we have 5 items:
There are 4!=24 ways of ordering these 4 items. However, we need to remember that B1+B2 can either be B1B2 or B2B1. So there are
possible orderings.
AHL AA 1.10
How many ways can the items B1,B2,B3,B4,B5 be ordered under the restriction that B1 and B2 must be together.
To solve questions like these, we treat the items that must stay together as a single unit. We consider that we have 5 items:
There are 4!=24 ways of ordering these 4 items. However, we need to remember that B1+B2 can either be B1B2 or B2B1. So there are
possible orderings.