Answer:
a) 21
b) 3905.44236
c) 251.94689
d) 1763.62824
Step-by-step explanation:
a) 42÷2=21
b) 60x42=2520
[tex]\pi[/tex]r²=1385.44236
2520+1385.44236=3905.44236
c) 2x[tex]\pi[/tex]x21=131.94689+60+60=251.94689
d) 251.94689x7=1763.62824