In March,
monthly allowance ——- 250
food ——- 50% x 250 = 125
books ——- 20% x 250 = 50
saved ——- 250 – 125 – 50 = 75

In April,
monthly allowance ——-  ?
food ——- (100% + 10%) x 125 = 137.50
books ——- (100% + 30%) x 50 = 65 (a)
saved ——- 250 – 125 – 50 = 75

(b)
137.50 + 65 + 75 = 277.50
277.50 – 250 = 27.50
(27.50/250) x 100% = 11%

Ans : (a) $65; (b) 11%.

Thanks . Saw my mistake as I  used 160% for food instead of 110%

My pleasure.