Page 20 - ACE YR IGCSE A TOP APPR' TO MATHS

Upper bound and lower bound

1 It is given that
P = 3.29, correct to 2 decimal places
Q = 5, correct to the nearest whole number
R = 0.046, correct to 2 significant figures
(a) Find the lower bound of the following expression, correct your answer to 2 decimal places.

(i) (PQ) 2

[3]
R – Q
(ii)
P

[3]
Q
(iii)
P – R

[3]

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(b) Find the upper bound of the following expression, correct your answer to 2 decimal places:
P + Q
(i)
R

[3]

(ii) (R – Q) 2

[3]

(iii) Q
PR

[3]

2 The side of a square is 3.8 cm, correct to 1 decimal place.
Calculate the lower bound for the area and perimeter of the square.

[4]

Chapter 1A Numbers 15

Chapter 1A.indd 15 15/03/2022 10:27 AM