► Skill Involving Two or more Quantities With Fixed Total
1. 30 pupils were asked to blow some balloons. Each boy blew 3 balloons and each girl blew 1 balloon. If the boys blew 38 balloons more than the girls, how many boys were there?
Ans :- 17.
2. There are 40 students in a class. 26 of them can swim, 30 of them can cycle and 6 of them can neither swim nor cycle. How many percent of the students can both swim and cycle?
Ans :- 55%.
3. 40 students sold some fun fair coupons. Each girl sold 5 coupons and each boy sold 2 coupons. The girls sold 32 more coupons than the boys. How many boys were there?
Ans :- 24.
4. Mr Mohan bought a certain number of cameras and watches for $1980. Each camera cost $60. Each watch cost ¼ as much as a camera. If 40% of the items bought were cameras, how many watches did he buy?
Ans :- 36.
5. Noel has 4 times as many pens as Kenny. If Noel gives Kenny 20 pens, he will have 7⁄8 as many pens as Kenny. How many pens does Noel have?
Ans :- Noel has 48 pens.
6. At a pub, a can of Coke cost $2. A can of beer cost thrice as much. On a certain day, the pub collected $800 from the sale of Coke and beer. If 30% of the two beverages sold was beer, how many cans of beer were sold?
Ans :- 75 cans of beers were sold.
7. A dictionary cost $20. A salesman was paid 10% commission for every dictionary he sold. He was paid another $30 for every 40 dictionaries sold. How many dictionaries did he sell if he was paid $710 altogether?
Ans :- He sold 265 dictionaries.
8. The number of apples in 3 bags is in the ratio of 2 : 5 : 9. If the third bag has 120 apples more than the second bag, how many apples must be taken from the third bag to be put in the first and second bags such that the number of apples in the first two bags will be 7⁄12 of the total number of apples?
Ans :- 70 apples.
9) After giving 22 cards away, Peter put the rest of the cards equally into boxes. He found that he had 7 cards left after putting 25 cards into each box. How many boxes of cards did Peter have if he had 154 cards at first?
Ans :- Peter had 5 boxes.
10) There are 2352 pupils in Heng Li High School. Each pupil has 12 lessons a day. Each teacher teaches 8 lessons a day. Each lesson involves 42 pupils and 1 teacher. How many teachers are there?
Ans :- There are 84 teachers.
11. In 2005 a salesman's monthly income was $1 200 for the first 8 months. It was 25% less for the rest of the year. His total income was 10% more than his total income in 2004. Find his average monthly income in 2004.
Ans :- $1000.