Home » Verbal Reasoning » Arithmetic Reasoning

Family composition puzzle (brothers and sisters): Use simultaneous conditions for sons and daughters. Each daughter has as many brothers as sisters. Each son has twice as many sisters as brothers. Find the number of sons in the family. Choose the correct value.

Difficulty: Medium

Correct Answer: 3

Explanation:

Let
b = number of sons, g = number of daughters.

Translate conditions
For a daughter: brothers = b, sisters = g − 1 ⇒ b = g − 1. For a son: sisters = g, brothers = b − 1 ⇒ g = 2(b − 1).

Solve
From b = g − 1 ⇒ b − 1 = g − 2. Plug into g = 2(b − 1): g = 2(g − 2) ⇒ g = 2g − 4 ⇒ g = 4. Then b = g − 1 = 3.

Final Answer
3 sons

← Previous Question Next Question→

More Questions from Arithmetic Reasoning

Age puzzle with reversed digits and ratio condition: Determine the woman's present age. When the woman's age digits are reversed, the result is her husband's age. He is older than she is. The difference between their ages equals one-eleventh of their sum. Find the woman's current age. Choose the correct value.
Sum of ages back in time: Adjust a current total to a past total. Present total age of Amar, Akbar, and Anthony = 80 years. Find the total of their ages three years ago. Choose the correct value.
Pigeonhole principle (socks in the dark): Guarantee a matching pair with two colors available. Drawer contains 20 black socks and 20 brown socks. Socks are drawn in the dark (no color visibility). Minimum number of socks to guarantee at least one matching pair? Choose the correct value.
Number theory/product trick: Multiply all the numbers on a telephone dial and identify the correct value. Telephone dial digits considered: 0 through 9. Find the product 0 × 1 × 2 × … × 9. Choose the correct value.
Linked ages with time shifts: Solve present ages from future and past relations. A is three times as old as B. Four years ago, C was twice as old as A was then. In four years' time, A will be 31. Find the present ages of B and C. Choose the correct ordered pair.
Family ages with mixed offsets: Determine parents' ages at a child's birth using given gaps. Brother is 3 years older than Ravi. Father was 28 when sister was born. Mother was 26 when Ravi was born. Sister was 4 when brother was born. Find the father's and mother's ages when the brother was born. Choose the correct ordered pair.
Shared-expense algebra: Determine the attending headcount from a per-person increase. Total planned spend on eatables = ₹96. Four friends did not turn up. Remaining attendees each paid ₹4 extra than originally planned. Find the number of friends who attended the picnic. Choose the correct value.
Two-condition age puzzle (father and son): Solve simultaneous relations to find the son's age. Now: Father's age = 3 × son's age. Five years ago: Father's age = 4 × son's age. Find the son's present age (in years). Choose the correct value.
Mixed-fruit purchase (linear Diophantine check): Find how many pineapples were bought. Pineapple costs Rs. 7 each; watermelon costs Rs. 5 each; total spend = Rs. 38. Assume only whole fruits can be purchased; determine the pineapple count. Choose the correct value.
Bus headcount equality after a stop: Find the initial total number of passengers. Initially, women count = half the men count. At city Y, 10 men alight and 5 women board; then men and women become equal. Compute the number of passengers at the beginning. Choose the correct total.

Discussion & Comments

No comments yet. Be the first to comment!

Join Discussion