Question

3 similar plates and 4 similar cups cost $35.50.while 3 such plates and 3 such cups costs $31.50.
what is the cost of 9 such plates.

Answer 1

let the cost of each plate be RS x

let the cost of eaach cup beRS y

according to the condition

3x+4y=35.5 ----eqn 1

3x+3y=31.5 -----eqn 2

solvin by substitution mehod we get

y=4

putting the value in eqn 2

3x+12=31

3x=19

x=19/3

cost of 1 plate is RS 19/3

cost of 9 succh plates=19/3*9

=19*3

=RS 57