P and Q entered into a partnership with initial investments of Rs. Y and Rs. Z respectively. After 18 months they both added some amount to their initial investments such that the investment of P for the rest of period is twice that of Q after added. Profit share of P is 17220 out of total profit of Rs. 28290 after three years. If Z is 50% more than that of Y, find by what % of Q increased his investment after 18 months?