The mass of Jessie was 72 kg. After joining a slim-fit programme, her mass decreased at a rate of 3 kg per month. Find the least number of complete months that Jessie has to be on the programme before her mass becomes less than 54 kg.
Juz wanna check: the answer given in the book is 6. Personally, I feel that the answer should be 7.
Pls enlighten...Thanx:)
Hi,
You may check via substitution, i.e.
72 - 3(6) = 54,
72 - 3(7) = 51 < 54.
Thanks.
Cheers,
Wen Shih