Answer:
a - 12 seconds (1/5 minute)
b - 5
Step-by-step explanation:
Answer:
4n^3-n^2-5n
Step-by-step explanation:
n(2n+4n2−5−3n)
=(n)(2n+4n2+−5+−3n)
=(n)(2n)+(n)(4n2)+(n)(−5)+(n)(−3n)
=2n2+4n3−5n−3n2
=4n3−n2−5n
Answer:
9
Step-by-step explanation:
Answer:
875
Step-by-step explanation:
lets assume the original amount X
the new amount = X - ( X × 40% )
525 = (60 × X) ÷ 100
X = ( 525 × 100 ) ÷ 60
<u>X = 875</u>
(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