In a shop, the cost of 4 shirts, 4 pairs of trousers and 2 hats is $560. The cost of 9 shirts, 9 pairs of trousers and 6 hats is $1,290. What is the total cost of 1 shirt, 1 pair of trousers and 1 hat?
It might be difficult to solve this outright with a system of equations because we might have more variables than equations.....let's see if we might arrive at some logical conclusion...
Note that if I divided the second thing by 3, we would have that
3 shirts, 3 pairs of trousers and 2 hats is $430
And taking the first we have that 4 shirts, 4 pairs of trousers and 2 hats is $560
Then. since the cost of the hats is the same, it must be that 1 shirt and 1 pair of trousers cost
$560 - $430 = $130
So....9 sets of each of them must cost 9 * $130 = $1170
So....the cost of a hat = [ 1290 - 1170] / 6 = 120/6 = $20
So....the total cost of 1 shirt, 1 pair of trousers and 1 hat = $130 + $20 = $150
Check
4(130) + 2(20) = $560
9(130) + 6(20) = $1290