Cost price of the article in $ | 64 |
-
Solution
Amount gained in $ when the article is sold for $84 is twice that gained when article is sold for $72.
Let the cost price of the article be x.
∴ 72 - x = 84 - 72 ∴ x = 60
Note that, when article is sold, for $72, the % gain is 20% and-when it is sold for $84, % gain is 40%.
Number of households that have only TVs | 35 |
-
Solution
No VCR owner owns only a VCR or a Radio, s it can be said that all 100 families own atleast one among a TV or a Radio. This is shown by figure zero in the Venn diagram.
∴ If out of 100 families, 75 own TV and 45 own a Radio, then (75 + 45) - 100 = 20 own both TV and Radio. Out of these 20, 10 own all the three.
Hence number of families having only TV and Radio = 10.
∴ Number of families owing only TV
= 75 - 10 - 10 - 15 = 40.
Number of children in the family | 7 |
-
Solution
Let g denote the number of girls and b denote the number of boys in the family. From the information given in the problem, it is clear that number of girls exceeds the number of boys by one.
But excluding Linda, we have b = g - I
Similarly, excluding Paul, including Linda 2(b - 1) = g + 1 - II
∴ 2b - 2 = g + 1 ∴ 2b - 2 = b + 1
∴ b = 3 ∴ g = 3 + 1= 4
Number of children = 7
Spirit content In liters In mixture of 64 liters | 28 |
-
Solution
9x2 - 30x + 25 = 0 ∴ (3x - 5)2 = 0
∴ Out of every 8 D2~s of mixture, sprit must be 3 parts and glycerin 5 because spirit is mixed in greater quantity of glycerin.
∴ In 64 liters we have 3⁄8 × 64 = 24 litres of spirit and remaining 40 litres of glycerin.
The start in m Paul can give Jack in a race of 600m | 5m |
-
Solution
When Linda gives Jack a start of 25m in a 300m race, it implies .that when Jack completes 300m, Linda completes 275m.
∴ In 600m race, Linda gives Jack a start of 50rn. On similar lines, in a 600m race, Linda gives Paul a start of 600 - \(\left (\frac{600\times 330}{360} \right )\)
= 600 - 550 = 50m
∴ Both Paul and Jack receive a start of 50m in 600m race.
∴ They cannot give each other any starts at all (i.e. start is zero m).
∴ Col. A = 0
Maximum number of figs she can buy | 34 |
-
Solution
To buy the maximum number of figs, she has to first buy the least number of oranges i.e. 30 .. -.30 oranges, 34 figs and 36 apples is a combination which gives the maximum number of figs and a total of 100 fruits
Ratio in which C1 and C2 are mixed | 3⁄4 |
-
Solution
S. P. = $44, Profit = 10% ∴ CP. = $40
∴ The cost price of the blend is $40 per kg.
By the principle of alligation
∴ C1 and C2 should be mixed in the ratio 5⁄8
Col. B = 3⁄4 = 6⁄8 ∴ Col. B > Col. A
Linda’s profit in the whole transaction | Paul’s profit in the whole transaction +$50 |
-
Solution
Linda's profit in the first transaction (i.e. with Paul): CP. = $600, S.P. = $700
∴ Profit = S.P.-CP. = $100
Linda's profit in the second transaction (i.e. with John) : CP. = $800, S.P. = $900
∴ Profit = S.P. - CP. = $100
∴ Linda's total profit = 100 + 100 = $200 = Col. A
Paul's profit in the whole transaction:
CP. $700,S.P.$800
∴ Profit = S.P.-CP. = $100
∴ Col. B = 100 + 50 = $150
Length of the journey in km | 630 km |
-
Solution
Distance = Speed × Time
Here distance remains constant.
∴ speed X time1 = speed2 × time2
∴ \(\frac{s_{1}}{s_{2}}=\frac{t_{2}}{t_{1}}\) ∴ \(\frac{45}{60}=\frac{t_{2}}{t_{1}}=\frac{3}{4}\)
Ratio of time taken for journey is 4 : 3
∴ 4x - 3x = 4.5 ∴ x = 4.5 ∴ 3x = 13.5, 4x = 18
∴ Length of journey = 45 × 18 = 810 kms.
Value of x | 60° |
-
Solution
The figure shows a polygon PQRSTUVWX with nine side.
Measure of the internal angle of this polygon
\(=\frac{(n-2)\times 180}{n}=\frac{(9-3)\times 180}{9}=\frac{7\times 180}{9}\)=140°
Now consider ΔSDT as shown in figure
∠RST = ∠STU = 140°
∴ y = 40° ........Angles in linear pair
∴ x = 180 - (40 + 40) = 100° = Col. A