Question

1. An 8-𝑚𝑒𝑡𝑒𝑟 ladder with its foot 4 𝑚𝑒𝑡𝑒𝑟𝑠 from the wall and slides away at a rate of 1.5 𝑚/s
2. A spherical balloon deflates at a rate of 18 𝑐𝑢. 𝑐𝑚 𝑝𝑒𝑟 𝑚𝑖𝑛𝑢𝑡𝑒 which initial radius is 6 𝑐𝑚. 
3. A 10-𝑓𝑒𝑒𝑡 steel bar 6 𝑓𝑡 from the ground and glides up at a rate of 1.8 𝑓𝑡 𝑝𝑒𝑟 𝑚𝑖𝑛𝑢𝑡𝑒.
4. A basketball being pumped with air which radius is 4.75 𝑖𝑛 that changes at a rate of 0.3 𝑖𝑛/𝑠𝑒𝑐. 

with solution please