KarishmaB wrote:
ziko wrote:
Rock750 wrote:
Since a metal bar weighs twice as much as a gold bar, 2M = G
Thus, by the equation given :
2M = (3/2 *M) + 15
M/2 = 15
M = 30
Hence,
Answer : D
Well here i faced confusion, i thought if 1 bar of mettal is twice havier than 1 bar of gold, for example 1 bar of M=4 kg then 1 bar of G=2 kg, that means 4=2*2 --> M=2G but not 2M=G, So according to my initial calculation i stuck then i decided to plug in and found D plausable.
But could anyone suggest whether my initial thinking was wrong?
Notice that M is the number of metal bars (not their weight)
And G is the number of gold bars.
If weight of a metal bar is twice the weight of a gold bar, and if you want to equate their weights, you will need twice the number of gold bars to make their weights equal.
That is how you get 2M = G (Number of gold bars should be twice the number of metal bars)
Question statement is "Metal bar weighs twice as much as gold bars"
this means;
m=2g (where m is metal bar weight & g is gold bar weight)
Now we need to get an equation having a variable of "No. of bars, not weight"
Suppose
M= No. of metal bar
G= No. of gold bar
above equation tells;
If the metal bar weight 4kg then the gold bar weight would be 2kg. Now consider this in terms of no. of bars, to equate 1bar of metal we need 2 bars of gold.
So, the equation would be
M=2G
2M = G didn't make any kind of understanding.