Question 19 — IGCSE 0580 Oct/Nov 2025 Paper 41
Cambridge IGCSE Mathematics 0580, Extended tier, calculator. Topic: Numbers · The four rules. Worth 3 marks.
Open in interactive question bank →
Question text
19 The mass of a radioactive substance decays exponentially at a rate of 10% per day.
The initial mass of the substance is 20 g.
Find the number of whole days it takes for the mass of the substance to first be less than 1 g.
......................................... days [3]
M
SIHT
NI
ETIRW
TON
OD
NIGRAM
SIHT
NI
ETIRW
TON
OD
Mark scheme
