1) Jia Xuan had a bottle containing some blue and red pebbles. After she had added 19 blue pebbles into the bottle, 30% of the pebbles in the bottle were blue. Then she added another 45 red pebbles into the bottle and 80% of the pebbles in the bottle were red. How many blue were there in the in the bottle at first?

Ans :- There were 8 pebbles in the bottle at first.

2) Amanda has $280 more than John. After Amanda spent 20% of her money and John spent 50% of his money, Amanda has $260 more than John in the end. How much does John have at first?

Ans :- John has $120 at first.

3) Lisa had 25% as much money as Ken at first. Lisa and Ken won $1304 and $10 respectively at a lucky draw. In the end, Lisa had 20% more money than Ken. How much money did Lisa have at first?

Ans :- Lisa had $340 at first.

4) Mr Lim bought some similar pens for $80. If he was given a discount of 20%, he would be able to buy 8 more pens with the same amount of money. What was the usual price of each pen?

Ans :- The usual price of each pen is $2.50

5) Old McDonald had a total of 840 chickens and ducks on his farm. 65% of them were chickens and the rest were ducks. After selling 300 chickens and ducks altogether, the percentage of chickens was reduced to 55%. How many ducks did he sell?

Ans :- He sold 51 ducks.

6) Kelly had 5100 beads. 20% of them were red. After Carol gave her some more red beads, the percentage of red beads increased to 40%.

(a) How many red beads did Kelly have at first?

(b) How many red beads did Carol give Kelly?

Ans :- a) Kelly had 1020 red beads at first.

b) Carol gave Kelly 1700 red Beads

7) George had some trading cards. He gave 75% of them to Mary and 20% of the remainder to Charlie. He then had 140 trading cards left.

(a) How many trading cards had George at first?

(b) How many percent more trading cards did Mary receive than Charlie?

Ans :- a) At first George had 700 cards.

b) Mary received 1400% more cards than Charlie.

8) Robert always spends 60% of his monthly income. His income in August was less than that in July. As a result, his expenditure in August decreased by $1134.

(a) If his expenditure in July was $2520, what was the percentage decrease in income in August?

(b) If Robert's expenditure in September was $756 more than his expenditure in August, what was the ratio of his income in September to his income in July?

Ans :- a) 45% decrease in income in August.

b) 17 : 20

9)Alicia gave some beads to Betty such that Betty had 40% of the number of beads that Alicia had. After that, Alicia gave another 170 beads to Betty. In the end, Betty had 80% of the number of beads that Alicia had. How many beads did Betty have in the end?

Ans :- In the end, Betty had 476 beads..

10) On Friday, Ann prepared 80 more fishballs than nuggets to sell at her stall. On Saturday, she prepared 30% less fishballs and 10% more nuggets compared to Friday. If she prepared a total of 290 fishballs and nuggets on Saturday, how many fishballs and nuggets did she prepare altogether on Friday?

Ans :- Altogether 340 fishball and nuggets

she prepared on Friday

11) In a school, there are 26 fewer male teachers than female teachers. The number of male teachers is 35% of the total number of teachers. How many teachers are there in the school?

Ans :- 180 teachers.