A and B compete in a race. A runs at a constant rate of 126 m/min while B runs 145 m the first minute, 143 m the second minute, 141 m the third minute and so on. When will A and B be together again? A. 15 min C. 20 min B. 30 min D. 25 min Click here to expand or… Jhun Vert Fri, 07/05/2024 - 06:19 Click here to expand or collapse this section $d_A = 126t$ $d_B = 145 + 143 + 141 + \ldots \, $ ← Sum of AP $d_A = d_B$ $126t = \frac{1}{2}t [ \, 2(145) + (t - 1)(-2) \, ]$ $t = 20 ~ \text{min}$ Log in or register to post comments Log in or register to post comments
Click here to expand or… Jhun Vert Fri, 07/05/2024 - 06:19 Click here to expand or collapse this section $d_A = 126t$ $d_B = 145 + 143 + 141 + \ldots \, $ ← Sum of AP $d_A = d_B$ $126t = \frac{1}{2}t [ \, 2(145) + (t - 1)(-2) \, ]$ $t = 20 ~ \text{min}$ Log in or register to post comments
Click here to expand or…