Solution to ES1:
Excess 11 Short 7
11 + 7 = 18
12 − 10 = 2 (Difference in number of marbles put into each bag)
18 ፥ 2 = 9 bags
Ans(a): 9 bags
Calculate total number of marbles:
9 × 10 = 90 90 + 11 = 101 (Number of marbles Ali bought)
Check:
9 × 12 = 108 108 − 7 = 101 (This answer must tally with the previous statement)
Ans(b): 101 marbles
Solution to ES2:
Excess $5.20 Short $14
$14 + $5.20 = $19.20
10 − 7 = 3 (Difference in number of wallets bought)
$19.20 ፥ 3 = $6.40 (Cost of each wallet)
Ans: $6.40
Calculate the amount of money Bala had with him at first:
10 × $6.40 = $64 $64 − $14 = $50 (Amount of money Bala had at first)
Check:
7 × $6.40 = $44.80 $44.80 + $5.20 = $50 (Both amounts must tally)
Ans: $50
Solution to ES3:
Excess 42 Short 12
42 + 12 = 54
15 − 12 = 3 (Difference in number of crayons given to each pupil)
54 ፥ 3 = 18 (Number of pupils Mrs Tan had)
Ans(a): 18 pupils
Calculate the number of crayons Mrs Tan had at first:
18 × 15 = 270 270 − 12 = 258 (Number of crayons Mrs Tan had at first)
Check:
18 × 12 = 216 216 + 42 = 258 (Both numbers must tally)
Ans(b): 258 crayons
Solution to ES4:
20 − 11 = 9 short (Each boy's share was 20 stamps)
Excess 7 Short 9
7 + 9 = 16
20 − 18 = 2 (Difference in number of stamps taken by each boy)
16 ፥ 2 = 8 (Number of boys sharing the stamps)
Ans(a): 8 boys
Calculate the number of stamps being shared:
8 × 20 = 160 160 − 9 = 151 (Number of stamps being shared)
Check:
8 × 18 = 144 144 + 7 = 151 (Both numbers must tally)
Ans(b): 151 stamps
Solution to ES5:
Excess 24 Short 6
24 + 6 = 30
11 − 8 = 3 (Difference in number of stickers given to each girl)
30 ፥ 3 = 10 (Number of girls in the class)
Ans(a): 10 girls
Calculate the number of stickers being given out:
10 × 8 = 80 80 + 24 = 104 (Number of stamps being shared)
Check:
10 × 11 = 110 110 − 6 = 104 (Both numbers must tally)
Ans(b): 104 stickers
