Question
The ratio of Rael's pens to Oliver's pens at first was 3 : 7. After Rael gave Oliver 80 pens, the ratio of Rael's pens to Oliver's pens is 1 : 3. What was the number of pens they had in total?
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The ratio of Rael's pens to Oliver's pens at first was 3 : 7. After Rael gave Oliver 80 pens, the ratio of Rael's pens to Oliver's pens is 1 : 3. What was the number of pens they had in total?