Question

Rearranging formula

Answer 1

Answer:

Arlo's weight = 52.3 kg

Explanation:

Let Arlo be "x"

Then,

Arlo = x

Bert = x+20 (Because Bert is 20 heavier than Arlo)

Cassie = x+20-5 (Because Cassie is 5 lighter than Bert)

Donnie = $\frac{x+20}{2}$ (Because Donnie is half of Bert's weight)

Average = 57

Step by step Calculations:

57 = $\frac{(x) + (x+20) + (x+20-5) + (\frac{x+20}{2} )}{4}$  (The whole divided by 4 because the total people is 4)

57*4   =  x + x + 20 + x + 20 - 5 + $\frac{x+20}{2}$

228 = 3x + 35 + $\frac{x+20}{2}$

228 - 3x - 35 = $\frac{x+20}{2}$

193 -3x = $\frac{x+20}{2}$

2(193 - 3x) = x + 20

386 - 6x = x + 20

386 - 20 = x + 6x

366 = 7x

x = $\frac{366}{7}$

x = 52.3 kg (corrected to 3 significant figures)

Therefore Arlo's weight is 52.3 kg