The easiest way to do this is to write the decimals with equal amount of places after the dot and you'll see it more clearly:
1.09 = 1.090
1.901 = 1.901
1.9 = 1.900
1.19 = 1.190
So from the least to the greatest:
1.090
1.190
1.900
1.901
In a form you gave at the beginning:
1.09 < 1.19 < 1.9 < 1.901
Answer:
Diapers costs $11 and formula is $13.
Step-by-step explanation:
Let's name diapers as A and formula as B.
Simply the equations:
1A + 2B = $37(1)
2A + 5B = $87(2)
Clear D from one equation.
A = $37 - 2B(1)
Replace D into the other equation.
2*($37 - 2B) + 5B = $87(2)
$74 - 4B + 5B = $87
$74 + B = $87
B = $87 - $74 = $13
Find A, now knowing B.
A = $37 - 2($13)
A = $37 - $26 = $11