CA FOUNDATION : MATH NOTES

Chapter : 1
UNIT : 2 -PROPORTION

EXERCISE 1(B)

Choose the most appropriate option (a) (b) (c) or (d).

1. The fourth proportional to 4, 6, 8 is
(a) 12 (b) 32 (c) 48
(d) none of these
Ans.

2. The third proportional to 12, 18 is
(a) 24 (b) 27 (c) 36
(d) none of these
Ans.

3. The mean proportional between 25, 81 is
(a) 40 (b) 50 (c) 45
(d) none of these
Ans.

4. The number which has the same ratio to 26 that 6 has to 13 is
(a) 11 (b) 10 (c) 21
(d) none of these
Ans.

5. The fourth proportional to 2a, a2, c is
(a) ac/2 (b) ac (c) 2/ac
(d) none of these
Ans.

6. If four numbers 1/2, 1/3, 1/5, 1/x are proportional then x is
(a) 6/5 (b) 5/6 (c) 15/2
(d) none of these
Ans.

7. The mean proportional between 12x2
and 27y2 is
(a) 18xy (b) 81xy (c) 8xy
(d) none of these
Ans.

8. If A = B/2 = C/5, then A : B : C is
(a) 3 : 5 : 2 (b) 2 : 5 : 3
(c) 1 : 2 : 5 (d) none of these
Ans.

9. If a/3 = b/4 = c/7, then a + b + c/c is
(a) 1 (b) 3 (c) 2
(d) none of these
Ans.

10. If p/q = r/s = 2.5/1.5, the value of ps : qr is
(a) 3/5 (b) 1:1 (c) 5/3
(d) none of these
Ans.

11. If x : y = z : w = 2.5 : 1.5, the value of
(x + z)/(y + w) is
(a) 1 (b) 3/5 (c) 5/3
(d) none of these
Ans.

12. If (5x – 3y)/(5y – 3x) = 3/4, the value of
x : y is
(a) 2 : 9 (b) 7 : 2 (c) 7 : 9
(d) none of these
Ans.

13. If A : B = 3 : 2 and B : C = 3 : 5, then
A : B : C is
(a) 9 : 6 : 10 (b) 6 : 9 : 10 (c) 10 : 9 :6 (d) none of these
Ans.

14. If x/2 = y/3 = z/7, then the value of
(2x – 5y + 4z)/2y is
(a) 6/23 (b) 23/6 (c) 3/2
(d) 17/6
Ans.

15. If x : y = 2 : 3, y : z = 4 : 3 then x : y : z is
(a) 2 : 3 : 4 (b) 4 : 3 : 2
(c) 3 : 2 : 4 (d) none of these
Ans.

16. Division of √ 750 into 3 parts in the ratio 4 : 5 : 6 is
(a) (200, 250, 300) (b) (250, 250, 250) (c) (350, 250, 150) (d) 8 : 12 : 9
Ans.

17. The sum of the ages of 3 persons is 150 years. 10 years ago their ages were in the ratio7 : 8 : 9. Their present ages are
(a) (45, 50, 55) (b) (40, 60, 50)
(c) (35, 45, 70) (d) none of these
Ans.

18. The numbers 14, 16, 35, 42 are not in proportion. The fourth term for which they will be in proportion is
(a) 45 (b) 40 (c) 32
(d) none of these
Ans.

19. If x/y = z/w, implies y/x = w/z, then the process is called
(a) Dividendo (b) Componendo
(c) Alternendo (d) none of these
Ans. (d) none of these

20. If p/q = r/s = p – r/q – s, the process is called
(a) Subtrahendo (b) Addendo
(c) Invertendo (d) none of these
Ans. (a) Subtrahendo

21. If a/b = c/d, implies (a + b)/(a – b) =
(c + d)/(c – d), the process is called
(a) Componendo (b) Dividendo
(c) Componendo and Dividendo
(d) none of these
Ans. (c) Componendo and Dividendo

22. If u/v = w/p, then (u – v)/(u + v) =
(w – p)/(w + p). The process is called
(a) Invertendo (b) Alternendo
(c) Addendo (d) none of these
Ans.(d) none of these

23. 12, 16, *, 20 are in proportion. Then * is
(a) 25 (b) 14 (c) 15
(d) none of these
Ans.

24. 4, *, 9, 13½ are in proportion. Then * is
(a) 6 (b) 8 (c) 9
(d) none of these
Ans.

25. The mean proportional between 1.4 gms and 5.6 gms is
(a) 28 gms (b) 2.8 gms (c) 3.2 gms (d) none of these
Ans.

26.

Ans.

27. Two numbers are in the ratio 3 : 4; if 6 be added to each terms of the ratio, then the new ratio will be 4 : 5, then
the numbers are
(a) 14, 20 (b) 17, 19 (c) 18 and24 (d) none of these
Ans.