Area = 7 x 7 + 1/2 x 7 x 3
= 49 + 10.5
= 59.5cm2
<span>So we want to know how much ball bearings can be made with 5.24 cm^3 if one ball bearing has a diameter of 1 cm. We know that radius r=d/2=0.5cm So the volume V of one ball bearing is: V=(4/3)*pi*r^3 so V=(4/3)*3.14*(0.5)^3cm^3=0.524cm^3. Now we simply divide the volume of steel by the volume of the ball bearing: 5.24/0.524=10. So we can make 10 ball bearings from 5.24 cm^3 of steel</span>
2 gophers per day are getting removed
Pairs, in this case, relates to a group of 2 or more. We have 6 friends. Let's call them A,B,C,D,E,F. This will allow us to make a [some sort of] combination tree:
1. ABC against DEF
2. ABD against CEF
3. ABE against CDF
4. ABF against CDE
5. ACD against BFE
6. ACE against BDF
7. ACF against BDE
8. ADE against BCF
9. ADF against BCE
10. AEF against BCD
I believe there are 12 combinations... I just can't think of the last 2 though.
