Step-by-step explanation:
4.
GCF : greatest common factor, the biggest number all these numbers can be divided by without remainder.
so, 15, 30 and 45
let's find the basic factors of each
15/2 no
15/3 = 5
5/3 no
5/4 no
5/5 = 1
therefore, 3¹×5¹
30/2 = 15
15/3 = 5
5/3 no
5/4 no
5/5 = 1
therefore, 2¹×3¹×5¹
45/2 no
45/3 = 15
15/3 = 5
5/3 no
5/4 no
5/5 = 1
therefore, 3²×5¹
the largest combination of factors they all have is 3¹×5¹ = 15
so, the GCF = 15.
5.
since I don't know how many pupils there are this is a strange question.
or does this text mean there are 5 pupils ?
overall, there is something wrong with this question.
so, let's answer based on some assumptions :
the GCF (as in 4.) is 12
12×3 = 36
12×4 = 48
12×5 = 60
so, if there are 12 students, each one gets 5 notebooks, 4 ball pens and 3 correction tapes.
if there are 5 students, then each one gets 60/5 = 12 notebooks, 48/5 = 9 (3 remainder) ball pens and 36/5 = 7 (1 remainder) correction tapes.
6.
multiples of 4, that means 4*x with x = 1, 2, 3, 4, ...
so
4×1 = 4
4×2 = 8
4×3 = 12
4×4 = 16
therefore, B is the right answer.
