There are 150 weights. Some are \(1 \mathrm{~kg}\) weights and some are \(2 \mathrm{~kg}\) weights. The sum of the weights is \(260 \mathrm{~kg}\).What is the number of \(1 \mathrm{~kg}\) weights?
A. 70 B. 55 C. 50 D. 40 E. 60
Correct Answer: D
Explanation
Say there are A \(1 \mathrm{~kg}\) weights and B two kg weights. Given, sum of weights \(=260 \mathrm{~kg}\) \(\Rightarrow A+2 \times B=260\) Given, there are 150 weights \(\Rightarrow A+B=150\) \(\therefore\) Eq.1-Eq.2 \(\Rightarrow B=110\)q.2 \(\Rightarrow A=150-B=150-110=40\) \(\therefore\) Number of \(1 \mathrm{~kg}\) weights \(=40\)
