51.

The third proportional of the following numbers (x - y)²,  (x² - y²)² is:

• (x + y)³ (x - y)²

• (x + y)⁴ (x - y)²

• (x + y)² (x - y)²

• (x + y)² (x - y)²

The numbers x, y, z are respectively proportional to 2 : 3 : 5 and the sum of x, y and z is 80. If the number z is given by the equation z = ax - 8, then a is

• 6

• 

• 3

• 

₹ 730/- were divided among A, B, C in such a way that if A gets â‚¹ 3/-, then B gets ₹ 4/- and if B gets â‚¹ 3.50/- then C gets â‚¹ 3/-. The share of B exceeds that of C by

• ₹ 30/-

• ₹ 40/-

• ₹ 70/-

• ₹ 210/-

A certain sum of money was divided between A, B and C in the ratio 5 : 6 : 9. If A received â‚¹ 450/-, the sum divided was:

• ₹ 2,000/-

• ₹ 1,800/-

• ₹ 2,250/-

• ₹ 1,000/-

The ratio of number of boys and girls in a school of 720 students is 7 : 5. How many girl should be admitted to make the ratio 1 : 1.

• 90%

• 120%

• 220%

• 240%

In an ornament the ratio of gold and copper is 3 : 2. The percentage of gold in the ornament is

• 60%

• 40%

• 30%

• 20%

If the ratio of two numbers is 1 : 5 and their product is 320, then the difference between the square of these two numbers is

• 1024

• 1256

• 1536

• 1435

Two numbers whose sum is 84, can do be in the ratio:

• 5 : 7

• 13 : 8

• 1 : 3

• 3 : 2

A and B together have Rs 6,300/-. If  of A's income is equal to  of B's amount. The amount of B is

• Rs 2,500

• Rs 3,800

• Rs 2,300

• Rs 4,000

If 60% of A = 3/4 of B,  then A: B  is

• 9 :  20

• 20 : 9

• 4 : 5

• 5 :  4