(a) there are 8C2 = 28 ways of picking 2 girls from 8
And there are 21C4 = 5985 ways of picking 4 boys
Required number of ways for 2g / 4b = 28 * 5985 = 167,580
(b) at least 2 girls means combinations of 2g/4b , 3g,3b , 4g/2b , 5g 1b or
6 girls.
2g/4b = 167,580 ways
3g/3b = 8C3 * 21C3 = 56 * 1330 = 74,480
4g/2b = 8C4* 21C2 = 70 * 210 = 14,700
5g 1b = 8C5* 21 = 56*21 = 1176
6 girls = 8C6 = 28
adding these up we get the answer to (b) which is 257,964
Surface=2(5 x 4)+2(4 x 7)+2(5 x 7)=2(20)+2(28)+2(35)=40+56+70=166
Answer: 166 cm²
Answer:
x>-4
Step-by-step explanation:
x-6>5x+10
x-5x>10+6
-4x<16
x<16/-4
x<-4
Answer is a if I am not mistaken