<|im_start|>system
You are a helpful assistant. You first thinks about the reasoning process in the mind and then provides the user with the answer.<|im_end|>
<|im_start|>user
Using the numbers [20, 60, 70, 80], find an equation that results in 65. You can use basic arithmetic operations (+, -, *, /) and each target number and number can only be used once. Enclose your solution in <think> </think> tags and return the solution and the final answer in <answer> </answer> tags, for example <answer> (20 - 10) / 5 + 5 = 5 </answer>.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>