Question

David and Joseph have a total of 328 marbles. Matthew and David have 176 marbles. Joseph has 5 times as many marbles as Matthew. How many marbles does David have?

Answer 1

D+J=328......(i)
M+D=176.....(ii)
J=5M
ADDING i AND ii
2D+M+J= 504
2D+6M=504
D+3M=252....(iii)
SUBTRACTING (ii) AND(iii)
2M=76
M=38
38+D=176
D=176-38=   138
DAVID HAS 138 MARBLES

Answer 2

David + Joseph = 328
Matt + David = 176 ---------------- (1)
Joseph = 5 x Matt

Total Marble = David + 5M + Matt + Davi = 504
 2 David + 6 Matt = 504
2 ( Davi + 3matt ) = 504  (common Term )
Davi + 3 Matt= 504/2 =252--------------------- (2)

sub equ (1) and (2)

M + D - (D + 3m) = 252 - 176 = 76
M+ D - D -3M = 76
2M = 76
M= 76/2 =38
M=38
So From Equation (1) we can write
M + D= 176
give the value of M
 
38 + D = 176
D= 176-38 =138

Marble in David's hand = 138