Question

what is the mass of the toolbox? image of a balance scale with a red toolbox on the left pan and various weights (labeled 1kg, 2kg, 5kg) on the right pan options: 18 kilograms, 16 kilograms, 14 kilograms

Explanation:

Step1: Identify weights on the scale

There are 4 weights of 1kg, 2 weights of 2kg, and 2 weights of 5kg.

Step2: Calculate total mass of weights

First, calculate the mass from 1kg weights: $4\times1 = 4$ kg.
Then, from 2kg weights: $2\times2 = 4$ kg.
Then, from 5kg weights: $2\times5 = 10$ kg.

Step3: Sum all masses

Total mass = $4 + 4 + 10 = 18$ kg? Wait, no, wait. Wait, let's count again. Wait, the image: let's see, the weights: first four are 1kg? Wait, maybe I miscounted. Wait, maybe the first four are 1kg, then two 2kg, then two 5kg? Wait, no, maybe the labels: let's check again. Wait, the problem's options: 18,16,14. Wait, maybe my initial count is wrong. Wait, let's re - examine. Suppose the weights are: four 1kg, two 2kg, and two 5kg? No, wait, maybe the 1kg weights: 4 of them (41 = 4), 2kg weights: 2 of them (22 = 4), 5kg weights: 2 of them (25 = 10). But 4 + 4+10 = 18. But maybe I made a mistake. Wait, maybe the 1kg weights are 4, 2kg are 2, and 5kg are 2? Wait, but let's check the sum again. Alternatively, maybe the weights are: four 1kg (4), two 2kg (4), and two 5kg (10). 4+4 + 10=18. But the options have 18. Wait, but maybe I miscounted the number of each weight. Wait, looking at the image: the right side of the balance has weights: first four small ones (let's say 1kg each), then two medium ones (2kg each), then two large ones (5kg each). So 41 + 22+25 = 4 + 4+10 = 18. But wait, maybe the 2kg weights are two, and 5kg are two, and 1kg are four. So total is 18. But let's check the options. The first option is 18 kilograms. Wait, but maybe I made a mistake. Wait, let's recalculate: 41 = 4, 22 = 4, 2*5 = 10. 4+4 = 8, 8 + 10=18. So the mass of the toolbox is equal to the total mass of the weights, so 18 kilograms. Wait, but maybe the 1kg weights are 4, 2kg are 2, and 5kg are 2. So yes, 18.

Answer:

18 kilograms