Solveit

number*100=percent

percent/100=number

so:

52/100 = 0.52=13/25

(162*x)/100=13

13/162*100 = 8.0246913580246914

t-total number of oranges

b-bag

o-orang

packs 10 Oranges in each bag,she will need 7 oranges more:

t-10b=-7

If she packs 9 oranges in each bag,she will have 3 extra oranges not packed

t-9b=3

so you have 2 equations now:

t-10b=-7   (minus them from each other)

t-9b=3

-b=-10

 b=10

put b=10 in one of the equations:

t-9b=3            b=10

t-90=3

t=93

but it is really cool answer I have t thought of that 15 right answers can be in different arrangement 

Thank you very much !! :)

it is not me :D

the number is 997920  sum is 36

2nd button atan

$V_{cylinder}= \pi r ^2 h \\ 300=\pi r^2h\\ h=\frac{300}{\pi r^2}$

so let s put our h=300/(pi r^2)  in $S_{cylinder}=2 \pi rh+2 \pi r^2$

$S_{cylinder}=2 \pi r( \frac{300}{\pi r^2 })+2 \pi r^2\\ S_{cylinder}=\frac{600}{r}+2 \pi r^2 \\ y=\frac{600}{x}+2\pi x^2 \text{ (so the minimum value of x is 3.628) }$

find the inverse of cos(1/2)

acos(1/2) = 60