By making suitable approximations, estimate the value of √(3.98 × 602.3) / 2.987 Show clearly the approximations you use.

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2016). The mark or mark type is shown in brackets.

1. [M1*] √3.98 ≈ √4 or 2, and 602.3 ~ 600 (or 602), and 2.987≈ 3 all three seen
2. B1 for two correct approximations. Could be implied by 2×200 or 1200/3.
3. [A1] (±)400 (or 401, 401.3 or better, from 602)
4. C1 for 400 WAW.