In how many ways can 4 different novels, 2 different mathematics books, and 1 biology book be arranged on a bookshelf if the novels must be together but the other books can be arranged in any order?

Pt = 576

Step-by-step explanation:

If 4 different novels must be together, we have 4 elements then

P₁  = 4!       P₁  = 4*3*2*1

 P₁  =  24

But now we have to consider  position between the novel group

P₂  =  4!      P₂    =  24

Total ways

Pt  =  24*24

Pt = 576

step-by-step explanation:

given perimeter: 28cm

length: 9cm

atp,

2(l+w)=p of the reactangle

2(9+x)=28

18+2x=28

2x=28-18

x=10/2

x=5

therefore width is 5 cm