A shop seller sells 3,4and 5 pack of sweet.he have 136 pack of sweet or 516 sweet in total. Given that 3 sweet of pack and 4 sweet of pack are 3 times the 5 sweet of pack.
Let n3 be the number of 3 sweet packs.
Let n4 be the number of 4 sweet packs.
Let n5 be the number of 5 sweet packs.
Then n3 + n4 + n5 = 136 (he have 136 pack of sweet)
n3*3 + n4*4 + n5*5 = 516 (or 516 sweet in total)
n3 + n4 = n5*3 (3 sweet of pack and 4 sweet of pack are 3 times the 5 sweet of pack.)
Substituting for n3 = n5*3 – n4 into the 1st two equations,
(n5*3 – n4) + n4 + n5 = 136
(n5*3 – n4)*3 + n4*4 + n5*5 = 516
Evaluating the above two eqns,
n5*4 = 136
n4 + n5*14 = 516
Substituting for n5 = 34 into the 2nd eqn above,
n4 + 34*14 = 516
n4 = 516 – 476
n4 = 40
Using n3 + n4 + n5 = 136
n3 + 40 + 34 = 136
n3 = 62
Number of 3-sweet bags = 62, Number of 4-sweet bags = 40, Number of 5-sweet bags = 34