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Date May 2018 Marks available 2 Reference code 18M.1.sl.TZ2.3
Level SL only Paper 1 Time zone TZ2
Command term Find Question number 3 Adapted from N/A

Question

Last year a South American candy factory sold 4.8 × 108 spherical sweets. Each sweet has a diameter of 2.5 cm.

The factory is producing an advertisement showing all of these sweets placed in a straight line.

The advertisement claims that the length of this line is x times the length of the Amazon River. The length of the Amazon River is 6400 km.

Find the length, in cm, of this line. Give your answer in the form a × 10k , where 1 ≤ a < 10 and k ∈ \(\mathbb{Z}\).

[3]
a.

Write down the length of the Amazon River in cm.

[1]
b.i.

Find the value of x.

[2]
b.ii.

Markscheme

4.8 × 108 × 2.5     (M1)

Note: Award (M1) for multiplying by 2.5.

1.2 × 109 (cm)     (A1)(ft)(A1)(ft) (C3)

Note: Award (A0)(A0) for answers of the type 12 × 108.

[3 marks]

a.

640 000 000 (cm)  (6.4 × 108 (cm))     (A1)

[1 mark]

b.i.

\(\frac{{1.2 \times {{10}^9}}}{{6.4 \times {{10}^8}}}\)     (M1)

Note: Award (M1) for division by 640 000 000.

= 1.88 (1.875)     (A1)(ft) (C3)

Note: Follow through from part (a) and part (b)(i).

[2 marks]

b.ii.

Examiners report

[N/A]
a.
[N/A]
b.i.
[N/A]
b.ii.

Syllabus sections

Topic 1 - Number and algebra » 1.3 » Expressing numbers in the form \(a \times {10^k}\) , where \(1 \le a < 10\) and \(k\) is an integer.
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