Question

Total number of students in a school are 750, out of which 30% are girls find the number of boys and girls​

Answer 1

Step-by-step explanation:

For doing things in your head(I find it easier to break down calculations into tenths, halves etc. Gets annoying with prime numbers but generally you get the answer without needing a calculator.) instead of multiplying/dividing by decimals/fractions, unless you're good with that :

100% = 750

50%=375, 10%=75, 2%=15

50%-4%=375–30

46%=345