jee-advanced 2000 Q8

jee-advanced · India · screening Inequalities Optimization Subject to an Algebraic Constraint
8. If $\mathrm { a } , \mathrm { b } , \mathrm { c } , \mathrm { d }$ are positive real numbers such that $\mathrm { a } + \mathrm { b } + \mathrm { c } + \mathrm { d } = 2$, then $\mathrm { M } = ( \mathrm { a } + \mathrm { b } ) ( \mathrm { c } +$ d) satisfies the relation :
(A) $0 \leq M \leq 1$
(B) $1 \leq \mathrm { M } \leq 2$
(C) $2 \leq M \leq 3$
(D) $3 \leq M \leq 4$
8. If $\mathrm { a } , \mathrm { b } , \mathrm { c } , \mathrm { d }$ are positive real numbers such that $\mathrm { a } + \mathrm { b } + \mathrm { c } + \mathrm { d } = 2$, then $\mathrm { M } = ( \mathrm { a } + \mathrm { b } ) ( \mathrm { c } +$ d) satisfies the relation :\\
(A) $0 \leq M \leq 1$\\
(B) $1 \leq \mathrm { M } \leq 2$\\
(C) $2 \leq M \leq 3$\\
(D) $3 \leq M \leq 4$\\