A building firm mixes concrete in equal batches.... | Mathematics Specification A 4MA1 | Paper 2 Mock 01 | Written Paper 2 (2F/2H)

Question 1 Report

A building firm mixes concrete in equal batches. Each batch uses 62.4 kg of cement, and 3 batches are needed for a job. Cement costs £0.20 per kg.

Work out the total mass of cement needed for the job. (2)
Work out the total cost of the cement. (2)
The firm has £40 set aside for cement. State, with a reason, whether this is enough. (1)

Answer

Answer Details

This question tests multiplying a mass per batch by the number of batches, finding the cost of that mass, and comparing the cost with a fixed budget.

The total mass of cement is the mass per batch multiplied by the number of batches: \(3 \times 62.4 = 187.2\) kg [2 marks].
The total cost is the mass multiplied by the price per kilogram: \(187.2 \times £0.20 = £37.44\) [2 marks].
Since \(£37.44\) is less than the £40 set aside, the budget is enough [1 mark].

Finding the total mass first, before applying the price per kilogram, avoids having to multiply three numbers together in a single step.

A building firm mixes concrete in equal batches. Each batch uses 62.4 kg of cement, and 3 batches are needed for a job. Cement costs £0.20 per kg. Work out ...