Trả lời câu hỏi của các bài sau PHIMO 2020 MOCK PAPER PRIMARY 4,8. Arrcttangular rrismiis dvvided into two ienntical figuresbbyccutinggaalong teemmrkkedlinn..WWat is,the surface area of one cut figure?,,(a) 500 square units (b) 510 squaree nnits,(c) 630 square units (d) 315 square units,9. 9. How many lateral faces does apprssm with 120 edges have?,(a) 60 $(b)~40$ (c) 42 (d) 62,10. An operator @ is defined as:,$2\otimes3=13$,$4\otimes2=20$,$3\otimes5=34$,$1\otimes3=10$,Find the value of 55 5,(a) 35 (b) 45 (c) 50 (d) 100

Question

Trả lời câu hỏi của các bài sau PHIMO 2020 MOCK PAPER PRIMARY 4,8. Arrcttangular rrismiis dvvided into two ienntical figuresbbyccutinggaalong teemmrkkedlinn..WWat is,the surface area of one cut figure?,<img src=https://minio.ftech.ai/cvdata/fqa/prod/public/illustration_images/c25cf0abc88d4524849c3721a8fac1c8.jpg />,(a)    500 square units (b)   510 squaree nnits,(c)    630 square units (d)   315 square units,9. 9.       How many lateral faces does apprssm with 120 edges have?,(a) 60 $(b)~40$ (c) 42 (d) 62,10.     An operator @ is defined as:,$2\otimes3=13$,$4\otimes2=20$,$3\otimes5=34$,$1\otimes3=10$,Find the value of 55   5,(a) 35 (b) 45 (c) 50 (d) 100

Accepted Answer

10. C
Ta thấy $\displaystyle ( 2\ imes \ 2) \ +\ ( 3\ imes \ 3) \ =\ 13$
$\displaystyle \begin{array}{{>{\displaystyle}l}}
( 4\ imes \ 4) \ +\ ( 2\ imes \ 2) \ =\ 20\
( 3\ imes \ 3) \ +\ ( 5\ imes \ 5) \ =\ 34\
( 1\ imes \ 1) \ +\ ( 3\ imes \ 3) \ =\ 10
\end{array}$
⟹ $\displaystyle ( 5\ imes \ 5) \ +\ ( 5\ imes \ 5) \ =\ 50$