ibps-rrb-os1 2021 · Question 87 of 173

A rectangle ABCD is given, whose sides AB and CD are equal. It is given that BC = X and CD = 2X+5. If area of rectangle is 168 sq. cm., then find the length of AB.

Quantitative Aptitude (misc)

A17 cm
B21 cmCorrect
C15 cm
D23 cm
ECND

Answer: B. 21 cm

Explanation

Area of rectangle = X(2X + 5) = 168 2X2 + 5X − 168 = 0 2X2 − 16X + 21X − 168 = 0 2X(X − 8) + 21(X − 8) (2X + 21)(X − 8) = 0 X = 8 So, AB = CD = 2 × 8 + 5 = 21 cm

Source: IBPS RRB PO Mains 2021 Memory Based Paper (Adda247/BankersAdda) · memory-based

Practice the full ibps-rrb-os1 2021 paper

Timed test with all 173 questions, just like the real exam.

Start test