Question

There is a mother holding her baby standing on a scale, their dog is sitting on the scale at the mother's feet. The scale reads 170 lbs. How much does the baby weigh if the mother weighs 100 pounds more than the combined weight of the baby and the dog, and the dog weighs 60% less than the baby?

a) 30 lbs
b) 40 lbs
c) 50 lbs

Answer 1

The baby weighs approximately 44 lbs.

Step-by-step explanation:

To solve this problem, let's assign variables to each unknown. Let's say the weight of the baby is represented by B, the weight of the mother is represented by M, and the weight of the dog is represented by D. We know that the scale reads 170 lbs, so we can set up the equation: M = B + D + 100. We also know that the dog weighs 60% less than the baby, so we can set up another equation: D = 0.6B. Now we can substitute the second equation into the first equation to get: M = B + 0.6B + 100. Combining like terms, we get: 1.6B + 100 = M. Since the scale reads 170 lbs, we can substitute M with 170 and solve for B: 1.6B + 100 = 170. Subtracting 100 from both sides gives us: 1.6B = 70. Dividing both sides by 1.6 gives us: B = 43.75. Therefore, the baby weighs approximately 44 lbs. So, the correct answer is option b) 40 lbs.