請教一題數學題，唔該將詳細解釋都講出來，please

首先,你要知道1=100%
按題設男生有x人,則女生有(x+x10%)人
男+女=全班人
x+(x+x10%x)=全班人
又因為x可以看做1乘以x
所以100%x+100%x+10%x=全班人
210%x=全班人
因為計人唔可能有小數
又因為210%=2.1
咁x=全班人/2.1
我就搵一個數字算係40人入邊,又可以比2.1整除ge數,即係21
即係x=21/2.1=10
上邊話左x係男生數,即係10個,女生係x+x10%,即係10個+(10乘10%=1個),所以女生11個

finish!

Let the no. of boy students be n where n is a positive integer (no. of students should be a positive integer, it cannot be a fraction or a negative no. )
Therefore the no. of girl students = n x (1 + 10%) = 1.1n
Total no. of students =( n + 1.1n) = 2.1n

2.1n is less than 40

n is less than 40/2.1
n is less than 19.0476

n can be 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19

But no. of girl students = 1.1n which has to be a whole no. because no. of girls cannot be a fraction. If 1.1n has to be a whole no., n can only be 10

Therefore the no. of girl students = 1.1n = 1.1x10 = 11