\[\boxed{\mathbf{411.}}\]
\[1)\ Яблоки,\ груши,\ морковь.\]
\[143 + 177 + 126 = 220 + 126 =\]
\[= 346\ г.\]
\[2)\ а)\ 198 + 198 = 396\ г.\]
\[\textbf{б)}\ 275 + 275 + 275 =\]
\[= 550 + 275 = 825\ г.\]
\[3)\ 346 \approx 300;\]
\[396 \approx 400;\]
\[825 \approx 800.\]