How many sweets?
Lena has 3 times as many sweets as Tom. After Lena gives 12 sweets to Tom, she now has twice as many sweets as he does.
How many sweets did Lena and Tom each have at the start?
Word Problem
A bridge is built across a river. One quarter of the bridge is over the left bank of the river and one third of the bridge is over the right bank. The river is 120 m wide. How long is the bridge?
Let the number of sweets Tom had at the start be x.
ReplyDeleteThen Lena had 3x sweets.
After giving away 12 sweets:
Lena now has: 3x - 12
Tom now has: x + 12
We're told Lena now has twice as many sweets as Tom:
3x - 12 = 2(x + 12)
Now solve:
3x - 12 = 2x + 24
3x - 2x = 24 + 12
x = 36
So:
Tom had 36 sweets at the start
Lena had 3 × 36 = 108 sweets at the start
Final Answer:
Tom had 36 sweets, and Lena had 108 sweets at the start.