Answer:
A. 350
B. (i) $686 (ii) 39 Hours
Step-by-step explanation:
Based on what's given..
A)
[tex]\sf S=B+8H[/tex]
[tex]\sf 710=B+8\times45[/tex]
[tex]\sf 710=B+360[/tex]
[tex]\sf B=710-360[/tex]
[tex]\boxed{\sf B= 350}[/tex]
B)
(i)
[tex]\sf S=350+8\times42[/tex]
[tex]\sf S=350+336[/tex]
[tex]\boxed{\sf S=686}[/tex]
(ii)
[tex]\sf 662=350+8H[/tex]
[tex]\sf 8H=662-350[/tex]
[tex]\sf H=312 \div 8[/tex]
[tex]\boxed{\sf H=39}[/tex]