Quant Boosters  Hemant Malhotra  Set 5

Q26) If A is twice more efficient as B, B is thrice more efficient as C, C is twice more efficient than D then what is the ratio A:B:C:D?

Let D = x
so C is twice more means C = x + 2x = 3x
and B is thrice more so 3 * 3x + 3x = 12x
and A will be Twice more =12 * 3 = 36x
so 36:12:3:1

Q27) Three athletes A, B and C run a race, B finished 24 meters ahead of C and 36 m ahead of A, while C finished 16 m ahead of A. If each athlete runs the entire distance at their respective constant speeds, what is the length of the race?

Initial gap is 4 then distance is 24,
For gap 16, d = 24 * 4 = 96

Q28) Running at a uniform speed in a race, A can beat B by 20 m, B can beat C by 10 m, and A can beat C by 28 m. How long is the race?

When A reaches the end point of race B is 20 m behind and C is 28 m behind so gap b/w B and C is 8 m . Now if B has to reach end point it needs to cover 20m and in this 20 m it is creating additional gap with C as 108 = 2 m so in 20 m it creates 2m gap. Hence in how many m it will create 10 m gap will be : 20*10/2 = 100

Q29) The breadth of a rectangle decreases by 33.33%. By what percent should the length be increased so as to maintain the same area?

Decrease of 33.33% means decrease of 1/3 means 3 becomes 2
so 2 will become 3
which means an increase of 50%

Q30) Trumph at the time of selling and purchasing, weighs 10% less and 20% more per kilogram respectively. Find the percentage profit earned by Trumph (Assuming he sells at Cost Price)

Method1 Let's say original weight is 100 now he is taking 20% extra so total 120 and selling 10% less so 90. So (12090/90) * 100 = 30/90 * 100= 33.33%
Method2 multiplying factor
1 * 10/9 * 6/5 = 1.33 so 33%