Answer:
Ivan had 288 sweet while Ken had 672 sweets
Step-by-step explanation:
Let the number of sweets owned by Ken and Ivan be k and v respectively.
After Ken gave away 5/7 of his sweet, what he had left
= k - 5k/7
= 2k/7
he had 2/3 as many sweets as Ivan then
2k/7 = 2v/3
Divide both sides by 2 and cross multiply
7v = 3k
Ivan then gave away 120 sweets, Ivan would have
v - 120 = k/4
multiply both sides by 4
4v - 480 = k
7v = 3(4v - 480)
7v = 12v - 1440
12v - 7v = 1440
5v = 1440
v = 1440/5
= 288
7v = 3k
7 * 288 = 3k
k = 7 * 288/3
= 672
