Let the original number be x
X^2 + 11 = 36
Subtract 11
X^2 = 25
Square root both
X = 5
Solution: her original number is 5
The following that are mathematical sentences are b,c
.2 m^3 is 10 percent
.2 m^3 is 10 percent
.2 m^3 is 10 percent
.1 m^3 is 5 percent
therefore
.7m^3 is 35%
.6m^3 is 10%
.3 m^3 is 5%
so .9m^3 is 15 %
all in .9m^3 +.7m^3 = 1.6 m^3 will be sand
