45 is my first choice answer
Step-by-step explanation:
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what is the problem ? you don't know how to add, subtract or multiply yet ?
sum of 57 and 16 : 57 + 16 = 73
difference of 61 and 31 : 61 - 31 = 30
the product of the sum and the difference :
73 × 30 = 2190
5.3 minutes.
First, let's calculate the volume of the tank. That will be the area of the base multiplied by it's length. And since it's base is a circle, the area is pi*r^2. So:
V = l*pi*r^2
V = 3.5 * pi * (2.2/2)^2
V = 3.5 * pi * (1.1)^2
V = 3.5 * pi * 1.21
V = 4.235 * pi
V = 13.30464489
So the tank has a volume of about 13.3 ft^3. Now simply divide that volume
by the rate of incoming fluid. So
13.3 / 2.5 = 5.32
Rounding to 2 significant figures gives a time of 5.3 minutes.
Shobo's age = x years
His mother's age = 6 times of Shobo's age
= 6x years
Five years from now
________________
Shobo's age = ( x + 5 ) years
According to the problem given,
x + 5 = one by third of his mother's
present age
x + 5 = 6x / 3
x + 5 = 2x
5 = 2x - x
5 = x
Therefore ,
Shobo's present age = x = 5 years
His mother's age = 6x
= 6 × 5
= 30 years