Unit 2
4 marks · Easya) Simplify the following using laws of indices: 5^3 × 5^2.
b) A rectangle has length 10 cm and width 3 cm. Work out its area. Give your answer in standard form.
Simplify the following using laws of indices: 5^3 × 5^2.
A rectangle has length 10 cm and width 3 cm. Work out its area. Give your answer in standard form.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) 5^5 or 3125
(b) 3.0 × 10^1 cm^2
Show mark scheme and worked solution
Marking points
M1 (a) · 1 mark · Uses laws of indices (adds the powers).
A1 (a) · 1 mark · Correct answer: 5^5 or 3125.
M2 (b) · 1 mark · Correctly calculates 10 × 3.
A2 (b) · 1 mark · Gives answer as 3.0 × 10^1 cm^2.
Worked solution
a) 5^3 × 5^2 = 5^{3+2} = 5^5 = 3125
b) Area = 10 × 3 = 30 cm^2 = 3.0 × 10^1 cm^2