Question
A man invested certain sum at simple interest of r% p.a.
such that it amounts to 170% of itself in 7 years. Find the interest earned when Rs. 2800 is invested at simple interest of r% p.a. for 3 years.Solution
Let the sum invested be Rs. ‘P’ Therefore, interest earned in 7 years = 1.7P – P = Rs. 0.7P ATQ; 0.7P = (P × r × 7) ÷ 100 Or, r = 70 ÷ 7 Or, r = 10 So, required interest earned = (2800 × 10 × 3) ÷ 100 = Rs. 840
If {x + (1/x)} = 4, then find the value of {x2 + (1/x2)}
x + y = 4, xy = 2, y + z = 5, yz = 3, z + x = 6 and xz =4, then find the value of x 3 + y 3 + z 3 – 3xyz.
...What will come in place of the question mark (?) in the following series?
23, 46, ?, 184, 368, 736
- If (x + y + z) = 14 and (xy + yz + zx) = 50, then find the value of (x² + y² + z²).
If (a – 8) 2 + (b + 2) 2 + (c – 3) 2 = 0, then find the value √(a +b + c).
...If (x - y) = 3, then find the value of (x³ - y³ - 9xy).
If x + y + xy = 118, such that x < y and both 'x' and 'y' are positive integers, then find minimum value of (x + y) .
If x + 1/x = 5 then find out the value of x⁵ + 1/(x⁵)?
If x = 8.15, y = 9.06 and z = –17.21, then the value of x³ + y³ + z³ – 3xyz is:
189500 – 22650 + 48× ? – 352×18 = 162674
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