Question: Barry wants to make a huge salad using only cucumbers and tomatoes. He will use a total of 280 pieces of vegetables. If there are thrice as many tomatoes as cucumbers, how many cucumbers will be used in the salad? Think carefully first, then make a decision:
Let c be the number of cucumbers and t the number of tomatoes. The total is the sum of the number of cucumbers and that of tomatoes, which is c + t = 280 piece of vegetables. Since there are thrice as many tomatoes as cucumbers, this means c = t / 3. Therefore 3 * c = t. The sum will therefore be c + 3 * c = 280 pieces of vegetables. This means that 4 * c = 280 vegetables. Therefore c = 280 / 4 = 70 cucumbers. So the answer is 70.